Automated drill bit re-sharpening and verification system

ABSTRACT

A completely automated apparatus for verifying the identity and geometry of drill bits, re-sharpening the cutting tip of a drill bit and re-positioning a locating ring upon the shank portion of the drill bit subsequent to the re-sharpening of the cutting tip thereof. The apparatus comprises a housing having a pair of cassette trays, a pair of grinding assemblies, a pair of optical assemblies, a pair of primary cleaning assemblies, a pair of secondary cleaning assemblies, a pair of inversion assemblies, a pair of workhead assemblies, a bumping assembly, and a loader assembly attached thereto. The workhead and loader assemblies are used to transport drill bits between the cassette trays and other assemblies in a selected sequence which is controlled and coordinated by a programmable control device. The control device is electrically interfaced to each of the assemblies and allows the cutting tip re-sharpening and locating ring re-positioning processes to be conducted simultaneously on at least two drill bits.

RELATED APPLICATIONS

[0001] The present application is a continuation-in-part of U.S.application Ser. No. 09/082,590 entitled AUTOMATED DRILL BITRE-SHARPENING AND VERIFICATION SYSTEM filed May 21, 1998.

FIELD OF THE INVENTION

[0002] The present invention relates generally to devices forre-sharpening machine tools, and more particularly to a completelyautomated system which verifies the identity and geometry of drill bits,re-sharpens the drill bits to within closely held tolerances, verifiesre-sharpened drill bit tolerances, adjusts the positioning of a locatingring disposed upon the shank of the re-sharpened drill bits, cleans there-sharpened drill bits and subsequently packages the same.

BACKGROUND OF THE INVENTION

[0003] The manufacture of printed circuit boards has experiencedconsiderable improvement over recent years. Technological advancementsin chemistry, machinery, and materials have resulted in the ability toconsistently produce large volumes of printed circuit boards with densecircuitry patterns on a highly efficient basis. One particular area ofprogress has been in the drilling process associated with printedcircuit boards. An individual circuit board typically includes thousandsof small-diameter drilled holes which are used to connect variouscomponents to the board by accommodating the leads or pins thereof, toconnect the circuitry traces of one layer to another, to providereference points for subsequent processing, and to assist in mountingthe complete circuit board within its final housing. In one currentlyknown circuit board manufacturing process, a plurality of circuit boardsare drilled simultaneously by maintaining the circuit boards in acontiguous, overlapped orientation. In another currently knownfabrication technique, several circuit boards are placed on a panel forprocessing, with a single panel typically including tens of thousands ofdrilled holes.

[0004] As will be recognized, due to the extremely small diameter of theholes typically drilled in the printed circuit boards, the associateddrill bits are formed having small diameter cutting tips and are made ofan extremely hard, wear resistant material such as tungsten carbide.Though this material is resistant to wear, after a certain number ofdrilled holes (“hits”), the drill bit will typically deteriorate andwill no longer be sharp enough to maintain the diameter and tolerancerequirements for subsequent holes. Through experience, circuit boardmanufactures have approximated the rate at which drill bits dull. Basedupon this wear rate, the drill bit is typically replaced after a certainnumber of hits.

[0005] During the printed circuit board manufacturing process, the depthto which the cutting tip of the drill bit penetrates, i.e., extendsinto, the circuit board(s) must also be tightly controlled. In thisrespect, the drill bits used to facilitate the drilling operation aretypically provided with a locating ring disposed about the shank portionthereof which serves as a stop for accurately locating the drill bit,the collet, or the tool holder of the rotary drilling apparatus. Due tothe importance of tightly controlling the penetration depth of thecutting tip of the drill bit into the circuit board(s), the distanceseparating the cutting tip from the locating ring must itself be tightlycontrolled, thus necessitating the precise positioning of the locatingring upon the shank portion of the drill bit.

[0006] In view of the difficulty and expense associated with themanufacture of carbide drill bits with small diameter cutting tips, oncethe cutting tip of the drill bit becomes dull, the same is typicallyre-sharpened rather than being discarded. As will be recognized, due tothe importance of drilling all the holes within the circuit board(s)within closely held tolerances, the re-sharpening of the cutting tip ofthe drill bit must be accomplished in a precise, highly accurate manner.Additionally, since the re-sharpening procedure often results in aslight loss of length from the cutting tip region of the drill bit, thedistance separating the cutting tip from the locating ring must bemaintained within a certain, tightly controlled range. In this respect,the shortening of the drill bit which occurs as a result of there-sharpening procedure requires that the position of the locating ringupon the shank portion be adjusted so as to once again achieve thedesired separation distance between the locating ring and the sharpenedcutting tip.

[0007] The re-positioning of the locating ring upon the shank portion ofthe drill bit is typically accomplished manually through the utilizationof conventional measurement techniques and devices such as calipers.Additionally, the re-sharpening of the cutting tip of the drill bit andsubsequent measurement thereof to ensure compliance with tolerancerequirements are often accomplished manually. However, as will berecognized, such manual re-positioning and re-sharpening techniques areextremely time consuming and thus expensive, and oftentimes do notaccomplish the positioning of the locating ring relative the cutting tipand/or the re-sharpening of the cutting tip with the degree of accuracyneeded to ensure that the subsequent drilling operation will be properlyconducted.

[0008] There has yet to be developed in the prior art an completelyautomated system for accomplishing the verification of identity anddiffering geometries of various drill bits and the re-sharpening andre-positioning functions described above. One of the difficulties inautomating the re-sharpening process is that the size and condition ofthe cutting tip of the drill bit often varies. In this respect, thecutting tip may be dirty, worn, undersize in diameter and/or length,chipped, or broken. Additionally, drill bits are typically sent forre-sharpening in large quantities, with such quantities including drillbits that are from different manufacturers, have different dates oforiginal manufacture, are of differing styles and/or series, or arebeing subjected to a first or subsequent re-sharpening procedure.

[0009] The present invention specifically addresses the above-describeddeficiencies and obstacles by providing a completely automated systemwhich automatically verifies the identity and geometry of drill bits,re-sharpens the cutting tip of a drill bit to within closely heldtolerances, and accurately adjusts the positioning of the locating ringupon the drill bit subsequent to the re-sharpening of the cutting tipthereof.

SUMMARY OF THE INVENTION

[0010] In accordance with the present invention, there is provided anautomated apparatus for verifying the identity and geometry of drillbits and re-sharpening the drill bit having a shank portion including alocating ring positioned thereupon, and a fluted portion which defines acutting tip of the drill bit. In addition to functioning to re-sharpenthe cutting tip of the drill bit, the present automated apparatusfunctions to adjust the position of the locating ring relative to thecutting tip subsequent to the re-sharpening thereof.

[0011] In the preferred embodiment, the automated apparatus comprises ahousing or base table having at least one and preferably a pair ofcassette trays attached thereto, each of which is sized and configuredto accommodate multiple drill bit containers. Each of the drill bitcontainers includes a plurality of drill bits stored therewithin. Alsoattached to the housing is a pair of grinding assemblies, each of whichis used to grind the cutting tip of a drill bit, and a pair of vision oroptical assemblies, each of which is used to conduct an initialverification of the identity and geometry of the drill bit inspection ofthe cutting tip of a drill bit prior to the grinding thereof and a finalinspection of the cutting tip subsequent to the grinding thereof. Inaddition to the grinding and optical assemblies, attached to the housingis a pair of primary cleaning assemblies which are each used forcleaning the cutting tip of a drill bit prior to the initial inspectionthereof, and a pair of secondary cleaning assemblies which are each usedfor cleaning the cutting tip of a drill bit prior to the finalinspection thereof. Also attached to the housing is a pair of inversionassemblies for selectively directing one of the shank portion and thefluted portion of a drill bit generally vertically upwardly, and atleast one bumping assembly which is used for adjusting the position ofthe locating ring of a drill bit relative to its cutting tip subsequentto the final inspection thereof.

[0012] The automated apparatus of the present invention furthercomprises a pair of workhead assemblies which are each movably attachedto the housing and used for selectively transporting a drill bit betweenrespective ones of the optical, grinding, and secondary cleaningassemblies. Also movably or rotatably attached to the housing is arobotic loader assembly of the automated apparatus which is used toselectively transport drill bits from the cassette trays to respectiveones of the inversion assemblies if required by the orientation of thedrill bits within the drill bit containers, from the cassette trays orinversion assemblies to respective ones of the primary cleaningassemblies, from the primary cleaning assemblies to respective ones ofthe inversion assemblies, from the inversion assemblies to respectiveones of the workhead assemblies, from the workhead assemblies to thebumping assembly, and from the bumping assembly back to respective onesof the cassette trays.

[0013] In the present automated apparatus, a programmable control deviceis electrically interfaced to the grinding, optical, secondary cleaning,inversion, bumping, workhead, and loader assemblies to control andcoordinate the operations thereof in a manner allowing the cutting headre-sharpening and locating ring re-positioning processes to be conductedsimultaneously on at least two drill bits. In this respect, the controldevice is operable to cause the loader assembly to remove the drill bitsfrom each drill bit container one at a time, and return each of thedrill bits to the drill bit container from which it was removedsubsequent to the final inspection of the cutting tip or there-positioning of the locating ring.

[0014] In the preferred embodiment; the loader assembly of the automatedapparatus comprises a robotic arm which is rotatable about first, secondand third generally parallel loader axes, and movable linearly (i.e.,upwardly and downwardly) along the third loader axis. Attached to therobotic arm is a gripper which is adapted to receive and releasably holdone or two drill bits, and is pivotally movable relative to the thirdloader axis. The gripper itself comprises a pair of shaft members whichare pivotally connected to the robotic arm. Each of the shaft membershas an aperture extending therethrough which is sized and configured toreceive the shank portion of a drill bit. The gripper further comprisesa rotary actuator member which is connected to the robotic arm andmechanically coupled to the shaft members in a manner wherein themovement of the actuator results in the concurrent pivotal movement ofthe shaft members relative to the robotic arm. In addition to the shaftand actuator members, the gripper comprises an elongate vacuum tubewhich is fluidly connected to the apertures for selectively creatingnegative pressure therewithin. The creation of a vacuum within each ofthe apertures subsequent to the receipt of the shank portion of a drillbit thereinto facilitates the retention of the drill bit within thegripper of the loader assembly.

[0015] Each of the optical assemblies of the automated apparatuscomprises top and front cameras for generating images which are used todetermine the overall length of the drill bit, the diameter and geometryof the cutting tip thereof, and the condition of the margins thereof.The images generated by the top and front cameras are further used toindex the cutting tip to selected reference points. In addition to thetop and front cameras, each optical assembly further includes anillumination array for illuminating the fluted portion and the cuttingtip, and control logic which is operative to process and interpret theimages generated by the top and front cameras. The control logic of eachof the optical assemblies also interacts with the control device in amanner facilitating the regulation of the movement of each of theworkhead assemblies in a prescribed manner based on the generatedimages.

[0016] Each of the grinding assemblies comprises at least one grindermotor having a grinder head rotatably connected thereto. The grinderhead itself defines a grinding face. Each grinding assembly furthercomprises an adjustment mechanism which is attached to the grinder motorand is operative to selectively move the grinder head into and out ofcontact with the cutting tip of the drill bit based upon is the level ofcontact pressure exerted by the cutting tip against the grinding face.The adjustment mechanism itself comprises a housing having an elongateball screw rotatably mounted thereto. Mechanically coupled to the ballscrew is a stepper motor which is operative to selectively rotate theball screw in either a first direction or a second direction oppositethe first direction. Additionally, cooperatively engaged to the ballscrew is a linear bearing. In the adjustment mechanism, the rotation ofthe ball screw in the first direction facilitates the movement of thelinear bearing toward a respective workhead assembly. Conversely, therotation of the ball screw in the second direction facilitates themovement of the linear bearing away from the corresponding workheadassembly. The grinder motor is itself attached to the linear bearing.

[0017] Each of the primary cleaning assemblies of the automatedapparatus comprises a bath having a quantity of cleaning putty disposedtherein. The cutting tip of a drill bit is insertable into and removablefrom within the cleaning putty of each primary cleaning assembly via theloader assembly. Additionally, each of the secondary cleaning assembliescomprises a base member having a conveyor member movably attachedthereto. The conveyor member is selectively movable between extended andretracted positions relative to the base member, and includes a quantityof cleaning putty disposed thereon. In addition to the base and conveyormembers, each secondary cleaning assembly comprises an indexing memberwhich is attached to the base member and operable to index the conveyormember a prescribed incremental distance when the conveyor member ismoved from its extended position to its retracted position. The cuttingtip of a drill bit is insertable into the cleaning putty of a respectiveone of the secondary cleaning assemblies by a respective one of theworkhead assemblies, with such insertion occurring immediately prior tothe final inspection of the cutting tip by a respective one of theoptical assemblies.

[0018] Each of the workhead assemblies of the automated apparatuscomprises a base member which is reciprocally moveable relative to thehousing along a first axis. Rotatably connected to the base member is aswivel member which is rotatable about a second axis extending ingenerally perpendicular relation to the first axis. Movably attached tothe swivel member is a collet member which is adapted to receive andreleasably hold the shank portion of a drill bit. The collet member isreciprocally movable along and rotatable about a third axis whichextends in generally perpendicular relation to the second axis. Theinsertion of a drill bit into the collet and the removal of the drillbit from therewithin is accomplished via the loader assembly. Eachworkhead assembly further comprises a support member which is attachedto the base member and receives and supports a portion of the colletmember when the cutting tip is being ground by a respective one of thegrinding assemblies.

[0019] The bumping assembly of the automated apparatus comprises a drillseat which is attached to the housing for slidably receiving the shankportion of a drill bit. In addition to the drill seat, the bumpingassembly comprises an adjustment mechanism which is attached to thehousing and used for positioning the cutting tip a desired separationdistance from the drill seat, and a reciprocal ram assembly which ismovably attached to the housing and used for selectively bumping thelocating ring into abutting contact with the drill seat subsequent tothe shank portion being inserted into the drill seat and the cutting tipbeing positioned at the separation distance from the drill seat. Thedrill bit is insertable into and removable from within the drill seatvia the loader assembly.

[0020] Each of the inversion assemblies of the automated apparatuscomprises a base member and a rotatable inversion arm which is attachedto the base member and adapted to receive a drill bit. In addition tothe base member and inversion arm, each of the inversion assembliescomprises a locking pin which is attached to the base member formaintaining the drill bit within the inversion arm. Also attached to thebase member is an air stream generator of the inversion assembly whichis used to remove residual putty from the cutting tip of the drill bitwithin the inversion arm. Drill bits are inserted into and removed fromwithin the inversion arm of each of the inversion assemblies via theloader assembly.

[0021] Further in accordance with the present invention, there isprovided an automated method of re-sharpening a drill bit having a shankportion which includes a locating ring positioned thereupon and a flutedportion which defines a pair of margins and a cutting tip. The presentmethod employs the use of an automated re-sharpening apparatus whichincludes a pair of cassette trays, a pair of grinding assemblies, a pairof optical assemblies, a pair of primary cleaning assemblies, a pair ofsecondary cleaning assemblies, a pair of workhead assemblies, a bumpingassembly, and a loader assembly. In addition to re-sharpening thecutting tip of the drill bit, the present method also achieves there-positioning of the locating ring relative to the cutting tip ifnecessitated by the re-sharpening thereof.

[0022] The present method comprises the initial step of positioning atleast one, and preferably multiple drill bit containers onto respectiveones of the cassette trays, with each of the drill bit containersincluding a plurality of drill bits stored therewithin. Thereafter, thedrill bits are removed from each drill bit container one at a time viathe loader assembly. Such removal is accomplished by advancing theloader assembly over the drill bit and into contact with the locatingring positioned upon the shank portion thereof. Thereafter, negativepressure is created within the loader assembly at a level sufficient toretain the drill bit therewithin.

[0023] The drill bits may be oriented within each of the drill bitcontainers such that either the shank portion or fluted portion thereofis directed generally vertically upwardly. If, during the removal of adrill bit from within a respective drill bit container, the loaderassembly is advanced over the fluted portion, the drill bit isthereafter inserted into the rotatable arm of a respective one of theinversion assemblies via the loader assembly such that the flutedportion is directed generally vertically upwardly. Thereafter, thepressure within the loader assembly is equalized, with the loaderassembly then being retracted away from the drill bit. The inversion armis then rotated such that the shank portion is directed generallyvertically upwardly. Subsequent to this “flipping” of the drill bit, theloader assembly is advanced over the shank portion thereof and intocontact with the locating ring positioned thereupon. Negative pressureis then again created within the loader assembly at a level sufficientto retain the drill bit therewithin. The drill bit is then removed fromwithin the inversion arm via the loader assembly.

[0024] After the drill bit has been inverted and re-grasped by theloader assembly in the above-described manner, the fluted portion of thedrill bit protrudes from the loader assembly. The cutting tip of thedrill bit is then inserted into and removed from within the quantity ofcleaning putty of one of the primary cleaning assemblies via the loaderassembly. If, during the removal of the drill bit from within arespective one of the drill bit containers, the loader assembly isadvanced over the shank portion of the drill bit rather than the flutedportion thereof, the drill bit need not be inverted prior to thecleaning of the cutting tip thereof via a respective one of the primarycleaning assemblies since the fluted portion already protrudes from theloader assembly. Rather, subsequent to the removal of the drill bit fromwithin a respective one of the drill bit containers, the cutting tipthereof is inserted into and removed from within the quantity ofcleaning putty of one of the primary cleaning assemblies via the loaderassembly.

[0025] After being cleaned by one of the primary cleaning assemblies,the drill bit is inserted into the rotatable arm of a respective one ofthe inversion assemblies via the loader assembly such that the shankportion thereof is directed generally vertically upwardly. The pressurewithin the loader assembly is then equalized, with the loader assemblythen being retracted from the drill bit. The air stream generator isthen used to blow air onto the cutting tip of the drill bit to removeany residual cleaning putty therefrom. Thereafter, the inversion arm isrotated such that the fluted portion of the drill bit is directedgenerally vertically upwardly. The loader assembly is then advanced overthe fluted portion of the drill bit and into contact with the locatingring positioned upon the shank portion thereof. Negative pressure isthen again created within the loader assembly at a level sufficient toretain the drill bit therewithin, with the drill bit then being removedfrom within the inversion arm via the loader assembly.

[0026] After being removed from within the inversion assembly, the drillbit is transferred from the loader assembly to a respective one of theworkhead assemblies. More particularly, the shank portion of the drillbit is inserted into a respective one of the workhead assemblies via theloader assembly. Once releasably held within a respective workheadassembly, the fluted portion of each drill bit is inserted into theinterior of a respective one of the optical assemblies thereby.

[0027] Once inserted into a respective optical assembly, the overalllength of the drill bit is determined, as is the diameter of the cuttingtip and the condition of the margins. Thereafter, the cutting tip isindexed to a prescribed position. The determination of the overalllength of the drill bit is preferably accomplished by indexing thecutting tip to a first reference point on a second reference axisgenerated by the control logic of the optical assembly via the workheadassembly. This step is followed by determining the distance between thefirst reference point and a point of intersection between the firstreference axis and a second reference axis also generated by the controllogic of the optical assembly. The control logic of the optical assemblyis further operative to generate a reference line and a target line,with the step of indexing the cutting tip to a prescribed positionpreferably being initiated by the generation of the reference line alongthe cutting tip of the drill bit. Thereafter, the drill bit is rotatedvia the workhead assembly to adjust the angular orientation of thereference line relative to a third reference axis generated by thecontrol logic of the optical assembly to within a prescribed range. Thecutting tip is then indexed to a second reference point on the secondreference axis, with the target line thereafter being generated alongone of the margins of the fluted portion. Finally, the drill bit isrotated via the workhead assembly as needed to cause the target line tocross the point of intersection between the first and second referenceaxes. The drill bit is thereafter removed from within the opticalassembly via the workhead assembly.

[0028] After the initial evaluation of the fluted portion and thecutting tip of each drill bit has been completed by a respective opticalassembly, the cutting tip of each drill bit is ground via a respectiveone of the grinding assemblies. In particular, the cutting tip of eachdrill bit is moved into contact with a respective grinding assembly viathe workhead assembly in which the drill bit is releasably held. Afterits initial movement into the grinding assembly, the cutting tip of thedrill bit is backed away therefrom via the workhead assembly, and thenrotated approximately 180° thereby. Subsequent to such rotation, thecutting tip is then moved back into contact with and thereafter drawnback away from the grinding assembly. Importantly, the grindingoperation conducted on the cutting tip of each drill bit by a respectiveone of the grinding assemblies is governed by the initial evaluation ofthe fluted portion and cutting tip of the drill bit by the correspondingoptical assembly. Additionally, when the cutting tip of each drill bitis moved into contact with a respective one of the grinding assemblies,a portion of the collet member of the associated workhead assembly isadvanced through and supported by the support member of the workheadassembly to reduce the vibration of the cutting tip during the grindingprocess. During each of the grinding operations described above, thegrinding assembly may be retracted away from the cutting tip of thedrill bit in the event the contact pressure between the cutting tip andthe grinding assembly exceeds a prescribed level.

[0029] Subsequent to being ground, the drill bits are carried by theworkhead assemblies in which they are releasably held to respective onesof the secondary cleaning assemblies. As the workhead assemblyapproaches a respective secondary cleaning assembly, the conveyor memberof the secondary cleaning assembly is actuated to its extended position,thus placing a portion of the cleaning putty disposed thereon intohorizontal alignment with the cutting tip of the drill bit. The cuttingtip of the drill bit is then inserted into the cleaning putty of thesecondary cleaning assembly by the associated workhead assembly. Theconveyor member of the secondary cleaning assembly is then actuated backto its retracted position. Importantly, the movement of the conveyormember back to its retracted position causes the indexing memberattached to the base member of the secondary cleaning assembly to indexthe conveyor member a prescribed incremental distance. Such movement ofthe conveyor member causes the cutting tips of subsequently cleaneddrill bits to be inserted into different portions of the cleaning puttydisposed upon the conveyor member.

[0030] After being cleaned by respective ones of the secondary cleaningassemblies, the drill bits are re-inserted by the workhead assembliesinto respective ones of the optical assemblies. Within each opticalassembly, a final evaluation of the drill bit is conducted. In the finalevaluation, the overall length of the drill bit is determined, as is thegeometry of the cutting tip and condition of the margins thereof. Thedetermination of the overall length of the drill bit is accomplished inthe same manner previously described in relation to the initialevaluation. Subsequent to the completion of such measurements, the drillbit is then removed from within the optical assembly via the workheadassembly in which it is releasably held. The final evaluation of eachdrill bit also includes a determination as to whether the locating ringof the drill bit is properly positioned relative to the cutting tipthereof.

[0031] If it is determined that the positioning of the locating ringrelative to the cutting tip must be adjusted, the drill bit istransported from its associated workhead assembly to the bumper assemblyvia the loader assembly. In particular, the shank portion of the drillbit is inserted into a drill seat of the bumping assembly, with thecutting tip then being positioned at a desired separation distance fromthe drill seat. Thereafter, the locating ring is bumped into abuttingcontact with the drill seat. Subsequent to the completion of thisbumping operation, the drill bit is transported from the bumpingassembly back to a respective one of the cassette trays via the loaderassembly. More particularly, the drill bit is returned by the loaderassembly to the precise location in the drill bit container from whichit was initially removed. As will be recognized, if during the finalevaluation of the drill bit it is determined that the position of thelocating ring need not be adjusted, the drill bit is transporteddirectly from the workhead assembly to the proper cassette tray by theloader assembly. Additionally, if during the final evaluation of thedrill bit it is determined that there is a fault in the geometry of itscutting tip, the drill bit is not transported to the bumping assembly orto a drill bit container on one of the cassette trays, but rather isrejected to a separate location by the loader assembly.

[0032] In the present method, the drill bits need not necessarily beremoved from and returned to the cassette trays, and in particular thedrill bit containers positioned thereon, but rather may be removed fromany pick-up location and returned to any drop-off location.Additionally, in the present method, data corresponding to the initialand final evaluations of each of the drill bits processed by there-sharpening apparatus is preferably stored within the control device.This data may be used to facilitate the generation of a statisticalprocess control report regarding the processed drill bits. This data mayalso be used to generate a used drill profile which may itself be usedto adjust the manner in which the cutting tips of subsequently processeddrill bits are ground by the re-sharpening apparatus. Moreover, the datagenerated and stored in relation to the drill bits may be used tofacilitate the sorting thereof in a manner wherein the drill bits aretransported to respective ones of multiple drop-off locations accordingto the final evaluations related thereto.

[0033] In the above-described steps of the present method wherein theloader assembly is used to transport the drill bit between the workheadassemblies and the bumping assembly and between the bumping assembly andrespective ones of the cassette trays, such transport is accomplished inthe same manner previously described in relation to the removal of thedrill bit from one of the cassette trays via the loader assembly, theinsertion of the drill bit into and the removal of the drill bit fromwithin a respective one of the inversion assemblies by the loaderassembly both prior and subsequent to the initial cleaning of thecutting tip thereof, and the transfer of the drill bit from the loaderassembly to a respective one of the workhead assemblies. Moreparticularly, the loader assembly is initially advanced over the flutedportion of the drill bit and into contact with the locating ringpositioned upon the shank portion. Thereafter, negative pressure iscreated within the loader assembly at a level sufficient to retain thedrill bit therewithin. After the shank portion of the drill bit has beeninserted into either a workhead assembly, the drill seat of the bumpingassembly, or the drill bit container, the pressure within the loaderassembly is equalized, with the loader assembly then being retractedfrom the drill bit.

[0034] For each drill bit to be inserted into and removed from withinthe inversion arm of an inversion assembly, the drill seat of thebumping assembly, and the drill bit container, the drill bit must bemaintained in a generally vertical orientation by the loader assembly.However, to be inserted into and removed from within each workheadassembly, the drill bit must be maintained in a generally horizontalorientation by the loader assembly. As such, the loader assembly isadapted to pivot to accomplish the extension of the drill bit eithervertically or horizontally as needed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] These, as well as other features of the present invention, willbecome more apparent upon reference to the drawings wherein:

[0036]FIG. 1 is a perspective view of a drill bit container used withthe re-sharpening apparatus of the present invention, illustrating themanner in which multiple drill bits are stored therewithin;

[0037]FIG. 2 is a front perspective view of the re-sharpening apparatusof the present invention;

[0038]FIG. 2a is a perspective view of one of the cassette trays of thepresent re-sharpening apparatus, illustrating the manner in whichmultiple drill bit containers are positioned thereupon;

[0039]FIG. 3 is a top view of the re-sharpening apparatus of the presentinvention;

[0040]FIG. 4 is a partial cross-sectional view of one of the shaftmembers of the gripper of the loader assembly of the presentre-sharpening apparatus;

[0041]FIG. 4a is a side elevational view of the gripper of the loaderassembly, illustrating the manner in which it is pivotally movablerelative to the robotic arm of the loader assembly;

[0042]FIG. 4b is a perspective view of the gripper of the loaderassembly;

[0043]FIG. 5 is a perspective view of one of the inversion assemblies ofthe present re-sharpening apparatus, illustrating the manner in which adrill bit is maintained therein;

[0044]FIG. 6 is a perspective view of one of the workhead assemblies ofthe present re-sharpening apparatus;

[0045]FIG. 6a is a partial side elevational view of the collet member ofthe workhead assembly shown in FIG. 6;

[0046]FIG. 7 is a cut-away perspective view of one of the opticalassemblies of the present re-sharpening apparatus, illustrating themanner in which a drill bit is inserted into the interior thereof viaone of the workhead assemblies;

[0047]FIGS. 7a-7 d are step-by-step illustrations of the initialevaluation procedure conducted on a drill bit by each optical assemblyof the present re-sharpening apparatus;

[0048]FIG. 8 is a front perspective view of one of the grindingassemblies of the present re-sharpening apparatus;

[0049]FIG. 8a is a perspective view of one of the secondary cleaningassemblies of the present re-sharpening apparatus;

[0050]FIG. 9 is a partial cross-sectional view of the bumping assemblyof the present re-sharpening apparatus;

[0051]FIGS. 10a-10 c are step-by-step illustrations of the finalinspection procedure conducted on a drill bit by each optical assemblyof the present re-sharpening apparatus;

[0052]FIGS. 11a-11 n are step-by-step illustrations of the preferredsequence of operations conducted by the present re-sharpening apparatus;

[0053]FIGS. 12a-12 j are end views of the cutting tip of a drill bit,illustrating various possible conditions thereof subsequent to thecompletion of operations conducted by the present re-sharpeningapparatus; and

[0054]FIG. 13 is a rear perspective view of one of the two adjustmentunits which may be integrated into each of the two grinding assembliesof the present re-sharpening apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0055] Referring now to the drawings wherein the showings are forpurposes of illustrating a preferred embodiment of the present inventiononly, and not for purposes of limiting the same, FIGS. 2 and 3illustrate the completely automated drill bit verification andre-sharpening apparatus 10 constructed in accordance with the presentinvention. As will be described in more detail below, the apparatus 10is utilized to automatically verify the identity and geometry of a drillbit 16 and re-sharpen the cutting tip 12 included on the distal end ofthe fluted portion 14 of a drill bit 16 (shown in FIG. 1). The drill bit16 further includes a cylindrically configured shank portion 18 whichtransitions into the fluted portion 14 via a tapered region 20.Positioned upon the shank portion 18 is an annular locating or settingring 22. The locating ring 22, which is placed along the shank portion18 at a standardized position for subsequent use, is normally locatedabout 0.8 inches from the end 24 of the shank portion 18, and isfrictionally maintained at this position upon the shank portion 18.

[0056]FIG. 12j illustrates a cutting tip 12 having an optimum pointgeometry. As seen in FIG. 12j, the cutting tip 12 of the drill bit 16includes a chisel edge 200 which defines the distal-most point of thecutting tip 12. In addition to the chisel edge 200, the cutting tip 12includes an opposed pair of cutting edges 202. The lateral distancebetween the cutting edges 202 defines the web thickness WT of thecutting tip 12. In FIG. 12j, a center line CL is shown as bisecting thecutting tip 12 into two (2) identical halves. Those portions of thecutting tip 12 between the center line CL and the straight sections ofthe cutting edges 202 define the primary faces 204 of the cutting tip12. Those portions of the cutting tip 12 between the center line CL andthe arcuate sections of the cutting edges 202 define the secondary faces206 of the cutting tip 12. As seen in FIG. 7c, the fluted portion 14 ofthe drill bit 16 includes a pair of margins, each of which are of amargin width MW. The margins extend distally to the cutting tip 12 ofthe drill bit 16.

[0057] As previously explained, the drill bit 16 is typically fabricatedfrom carbide or tungsten carbide, and utilized in relation to themanufacture of printed circuit boards. The drill bit 14, and inparticular the fluted portion 14 thereof, is used to form a plurality ofsmall diameter holes within a single circuit board or a plurality ofoverlapped circuit boards for accommodating the pins or leads of theelectrical components which are to be subsequently interfaced to thecircuit board(s). In addition to the diameters of the holes within thecircuit board(s) needing to be held within close tolerances, the depthto which the cutting tip 12 of the drill bit 16 penetrates (i.e., isextended into) the circuit board(s) must also be accurately controlledto insure proper drilling tolerances. Such depth control is typicallyaccomplished through the axial positioning of the frictionally mountedlocating ring 22 upon the shank portion 18. In this respect, theextension of the shank portion 18 into the collet or tool holder of adrilling apparatus (not shown) is limited by the abutment of thelocating ring 22 thereagainst. Since the locating ring 22 serves as a“stop” for controlling the length of the drill bit 16 which extends fromthe tool holder, the distance D1 separating the cutting tip 12 from thelocating ring 22 must be maintained within a certain, close tolerancerange to insure proper circuit board drilling.

[0058] Due to the expense associated with the manufacture of the drillbit 16, after prolonged use, the cutting tip 12 is preferablyre-sharpened rather than the drill bit 16 being discarded. There-sharpening of the cutting tip 12 generally results in a decrease inthe length of the fluted portion 14, thus lessening the distance D1separating the cutting tip 12 from the locating ring 22. As such, afterthe re-sharpening procedure has been completed, the position of thelocating ring 22 upon the shank portion 18 must be adjusted tore-achieve the proper distance D1 separating the cutting tip 12 from thelocating ring 22. As also previously explained, in the prior art, there-sharpening of the cutting tip 12 as well as the re-positioning of thelocating ring 22 upon the shank portion 18 is typically done manually orsemi-manually through the use of various independent conventionalgrinding and measurement systems and techniques. However, the use ofthese prior art methods, in addition to being time-consuming and costly,often does not facilitate the required level of accuracy in the finishedconfiguration of the cutting tip 12 and/or the distance D1 separatingthe cutting tip 12 from the locating ring 22.

[0059] Drill Bit Container

[0060] As further seen in FIG. 1, for processing by the presentapparatus 10, drill bits 16 (including the locating rings 22 positionedthereupon) are preferably stored in a drill bit container 26. The drillbit container 26 comprises a base 28 having a cover 30 pivotallyconnected thereby via a pair of hinges 32. To secure the cover 30 to thebase 28, a first tab 34 of the cover 30 mates with a second tab 36 ofthe base 28. As such, the drill bit container 26 can assume either anopened position or a closed position, and is shown in FIG. 1 in itsopened position.

[0061] The base 28 of the drill bit container 26 defines a generallyflat top surface 38 having a plurality of drill bit receiving holes 40disposed therein. The drill bit receiving holes 40 are specificallyarranged in the top surface 38, and are provided in alternately off-setrows for purposes of reducing the overall size requirement for the drillbit container 26. Each of the drill bit receiving holes 40 has adiameter which is large enough to allow the shank portion 18 of thedrill bit 16 to pass therethrough. However, each drill bit receivinghole 40 is smaller in diameter than the locating ring 22. As such, theinsertion of the shank portion 18 axially into a respective one of theholes 40 is limited by the abutment of the lower surface of the locatingring 22 against the top surface 38 of the base 28. As such, the majorityof the shank portion 18 resides below the top surface 38, with thefluted portion 14 projecting generally perpendicularly upwardlytherefrom. Although the particular container 26 illustrated herein ismanufactured by Tycom Corp. of Santa Ana, Calif., the assignee of thispatent application, those of ordinary skill in the art will recognizethat other containers 26 manufactured by alternative companies may beutilized in the present invention and are clearly contemplated herein.

[0062] The drill bit container 26 used in conjunction with the apparatus10 may be of a standard design, or alternatively of any special designas required by a customer. Additionally, the drill bits 16 need not beinserted into respective ones of the receiving holes 40 such that thefluted portions 14 thereof project generally perpendicularly upwardlyfrom the top surface 38. Rather, as further seen in FIG. 1, the flutedportion 14 of each drill bit 16 may be axially inserted into arespective one of the holes 40, with such insertion being limited by theabutment of the upper surface of the locating ring 22 against the topsurface 38 of the base 28. In this orientation, the shank portion 18 ofthe drill bit 16 will project generally perpendicularly upwardly fromthe top surface 38.

[0063] Apparatus Housing

[0064] Referring now to FIGS. 2 and 3, the apparatus 10 of the presentinvention comprises a base table or housing 42 which defines a planartop surface 44 having a generally rectangular configuration. The housing42 is preferably modularly configured, and includes a center section 42a and a pair of identically configured end sections 42 b, 42 c which areabutted against respective ones of opposed sides of the center section42 a. The top surfaces of the center and end sections 42 a, 42 b, 42 ccollectively define the top surface 44. Attached to the front of thehousing 42, and more particularly respective ones of the end sections 42b, 42 c thereof, is a pair of control panels 46, at least one of whichhouses a programmable control device, the use of which will be describedin more detail below. Attached to the top surface of the center section42 a is a rectangularly configured support plate 50. Additionally,attached to the top surface of each of the end sections 42 b, 42 c is apair of generally rectangular support blocks 48, i.e., two (2) pairs ofthe support blocks 48 are attached to the top surface 44. One pair ofopposed sides of the support plate 50 are abutted against respectivepairs of the support blocks 48, with the remaining pair of opposed sidesbeing substantially flush with respective ones of the longitudinal sidesof the center section 42 a of the housing 42. The support blocks 48 andsupport plate 50 each define generally planar top surfaces.

[0065] Cassette Trays

[0066] Referring now to FIGS. 2, 2a and 3, the apparatus 10 of thepresent invention comprises a pair of elongate, generally rectangularcassette trays 54 which are attached to the generally planar topsurfaces of respective pairs of the support blocks 48. As seen in FIGS.2 and 3, the width dimensions of the identically configured cassettetrays 54 are substantially identical to those of the support blocks 48to which they are attached. In this respect, the longitudinal andlateral sides of each cassette tray 54 are substantially flush with thecorresponding sides of the support blocks 48 to which it is attached.

[0067] In the apparatus 10, each cassette tray 54 is a frame having aplurality of generally rectangular, equally sized openings 56 formedtherein. The openings 56 are each defined by frame walls 58 whichproject upwardly from a base 60. Importantly, each of the openings 56has a configuration which is complementary to that of the base 28 of thedrill bit container 26. In this respect, as seen in FIG. 2a, eachopening 56 is sized to partially receive the base 28 of a drill bitcontainer 26 and hold the same in a set position. As also seen in FIG.2a, drill bit containers 26 may be placed within the openings 56 in apattern wherein an opening 56 adjacent the base 28 of each drill bitcontainer 26 is used to accommodate the cover 30 when the drill bitcontainer 26 is opened. However, those of ordinary skill in the art willrecognize that the bases 28 of drill bit containers 26 may be insertedinto all of the openings 56 at one time provided that the covers 30 aredetached therefrom.

[0068] Loader Assembly

[0069] Referring now to FIGS. 2, 3, 4, 4 a and 4 b, the apparatus 10 ofthe present invention includes a robotic loader assembly 62 which ismovably or rotatably attached to the support plate 50 and is used toremove drill bits 16 one at a time from within the drill bit containers26 positioned upon the cassette trays 54, and return each drill bit 16to the precise location within the drill bit container 26 from which itwas removed subsequent to the re-sharpening of its cutting tip 12 andre-positioning of its locating ring 22. The loader assembly 62 is alsoused to transport drill bits 16 between various assemblies of theapparatus 10, as will be described in more detail below.

[0070] The loader assembly 62 comprises a robotic arm having a generallyL-shaped first arm segment 64 which is rotatably attached to a basemember 65 of the loader assembly 62. The base member 65 is itselfattached to the top surface of the support plate 50 in relative closeproximity to the back edge thereof. As seen in FIG. 2, the first armsegment 64 is rotatable relative to the base member 65 about a firstloader axis LA1 which extends in generally perpendicular relation to thetop surface of the support plate 50. In addition to the first armsegment 64, the robotic arm comprises a second arm segment 66 which isrotatably connected to the distal end of the horizontally extendingportion of the first arm segment 64 and is rotatable about a secondloader axis LA2 relative thereto. As further seen in FIG. 2, the secondloader axis LA2 extends in generally parallel relation to the firstloader axis LA1.

[0071] In addition to the first and second arms segments 64, 66, therobotic arm of the loader assembly 62 comprises a third arm segment 67which is rotatably connected to the end of the second arm segment 66opposite that connected to the first arm segments 64. The third armsegment 67 is rotatable about a third loader axis LA3 relative to thesecond arm segment 66. The third loader axis LA3 itself extends ingenerally parallel relation to the first and second loader axes LA1,LA2. In addition to being rotatable about the third loader axis LA3, thethird arm segment 67 of the robotic arm is movable linearly orvertically (i.e., upwardly and downwardly) therealong. Though not shown,the robotic arm of the loader assembly 62 includes internal componentswhich allows the first arm segment 64 to be rotated about the firstloader axis LA1, the second arm segment 66 to be rotated about thesecond loader axis LA2, and the third arm segment 67 to be rotated aboutor moved along the third loader axis LA3.

[0072] In addition to the robotic arm, the loader assembly 62 comprisesa gripper 70 which is attached to the lower end of the third arm segment67 of the robotic arm. The gripper 70 comprises a gripper housing 71 ahaving a pair of gripper arms 71 b extending downwardly therefrom inspaced, generally parallel relation to each other. The gripper 70further comprises a pair of shaft members 72 which are pivotallyconnected to respective ones of the gripper arms 71 b. Moreparticularly, each of the shaft members 72 extends partially between aspaced pair of flange portions defined by a respective gripper arm 71 b.Extending longitudinally through each shaft member 72 is an aperture 74,at least a portion of which has a diameter slightly exceeding thediameter of the shank portion 18 of the drill bit 16. Fluidly connectedto each of the apertures 74 is an elongate, flexible vacuum tube 76 ofthe loader assembly 62 which is also connected to a vacuum pump thereof.When activated, the vacuum pump facilitates the creation of a vacuumwithin each of the apertures 74 for reasons which will be described inmore detail below.

[0073] In addition to the shaft members 72, the gripper 70 comprises anactuator member 78 which is used to facilitate the reciprocal pivotalmovement of the shaft members 72 relative to the third loader axis LA3.The actuator member 78 preferably comprises a pneumatic cylinder, thebody of which is pivotally connected to one of the gripper arms 71 b.Extending axially from the body is a piston rod, the distal end of whichis mechanically coupled to the pivot pin used to pivotally connected theshaft members 72 to the gripper arms 71 b and each other.

[0074] As seen in FIGS. 4 and 4a, the shaft members 72 of the gripper70, in addition to having the capacity to rotate about and travelvertically along the third loader axis LA3 by virtue of the connectionof the gripper 70 to the third arm segment 67, may also be pivotedapproximately 90° to a horizontal orientation by the actuator member 78so as to extend along a gripper axis GX which is generally perpendicularto the third loader axis LA3. In this respect, the advancement of thepiston rod of the actuator member 78 from the body thereof facilitatesthe upward pivotal movement of the shaft members 72 from a verticalorientation extending along the third loader axis LA3 (as shown in FIGS.4 and 4b) to a horizontal orientation extending along the gripper axisGX (as shown in FIG. 4a). Conversely, the retraction of the piston rodback into the cylinder facilitates the downward pivotal movement of theshaft members 72 and the return thereof to their extension along thethird loader axis LA3. The importance of the ability to extend the shaftmembers 72, and in particular their apertures 74, along the gripper axisGX will be described in more detail below.

[0075] As is apparent from the foregoing description of the loaderassembly 62, the shaft members 72 of the gripper 70 thereof may bemaneuvered to a position above virtually any location upon the topsurface 44 of the housing 42 by the robotic arm. Importantly, theconfiguration of the cassette trays 54 and their attachment to thesupport blocks 48 is such that a drill bit 16 disposed within any drillbit receiving hole 40 of a drill bit container 26 stored within anyopening 56 of the cassette trays 54 is accessible by the gripper 70 ofthe loader assembly 62, and in particular either of the shaft members 72thereof.

[0076] As further seen in FIG. 4, the “grasping” of a drill bit 16 bythe loader assembly 62 when the drill bit 16 is vertically oriented withthe fluted portion 14 thereof projecting upwardly is accomplished byinitially maneuvering one of the shaft members 72 via the robotic armsuch that the aperture 74 extending therethrough is coaxially alignedwith the fluted portion 14 of the drill bit 16. Thereafter, the shaftmember 72 is moved vertically downward along the third loader axis LA3and advanced over the fluted portion 14 and tapered region 20 of thedrill bit 16, with such downward advancement being terminated when theshaft member 72 contacts the locating ring 22 of the drill bit 16.Thereafter, the vacuum pump of the loader assembly 62 is activated so asto create negative pressure within the aperture 74. Such negativepressure or vacuum causes the drill bit 16 to be retained within theshaft member 72 when the same is moved upwardly along or rotated aboutthe third loader axis LA3 by the third arm member 67 of the robotic arm.As will be recognized, the equalization of pressure within the aperture74 as occurs when the vacuum pump is deactivated results in theimmediate release of the drill bit 16 from within the shaft member 72.

[0077] The “grasping” of the drill bit 16 by the loader assembly 62 whenthe drill bit 16 is vertically oriented with the shank portion 18thereof projecting upwardly is accomplished in the previously describedmanner as well. In this respect, one of the shaft members 72 of thegripper 70 is initially maneuvered such that the aperture 74 extendingtherethrough is coaxially aligned with the shank portion 18 of the drillbit 16. Thereafter, the shaft member 72 is moved vertically downwardalong the third loader axis LA3 and advanced over the shank portion 18,with such downward advancement being terminated when the shaft member 72contacts the locating ring 22 of the drill bit 16. Once again, thevacuum pump of the loader assembly 62 is activated so as to createnegative pressure within the aperture 74 which causes the drill bit 16to be retained within the shaft member 72. The equalization of pressurewithin the aperture 74 resulting from the deactivation of the vacuumpump facilitates the immediate release of the drill bit 16 from withinthe shaft member 72.

[0078] As is apparent from FIG. 4a, the “grasping” of a drill bit 16 bythe loader assembly 62 when the drill bit 16 is horizontally oriented isaccomplished by maneuvering one of the shaft members 72 via the roboticarm such that when the shaft member 72 is pivoted upwardly by theactuator member 78, the gripper axis GX is coaxially aligned with thedrill bit 16, and in particular the fluted portion 14 thereof.Thereafter, the shaft member 72 is moved horizontally and advanced overthe fluted portion 14 and tapered region 20 of the drill bit 16, withsuch horizontal advancement being terminated when the shaft member 72contacts the locating ring 22 of the drill bit 16. The activation of thevacuum pump of the loader assembly 62 retains the drill bit 16 withinthe shaft member 72 in the previously described manner.

[0079] Primary Cleaning Assemblies

[0080] Referring now to FIGS. 2 and 3, the apparatus 10 of the presentinvention further includes a pair of identically configured primarycleaning assemblies 80 which are each used to facilitate the cleaning ofthe cutting tip 12 of a drill bit 16 prior to the grinding orre-sharpening thereof. Although not by limitation, in the preferredembodiment, the primary cleaning assemblies 80 each comprise arectangularly configured bath or container 82 which is attached to arespective one of the support blocks 48, and more particularly thelongitudinal side thereof disposed adjacent the support plate 50. Eachof the baths 82 contains a quantity of cleaning putty 84.

[0081] In the apparatus 10, if a drill bit 16 has initially been graspedby a shaft member 72 of the gripper 70 via the advancement of the shaftmember 72 over the shank portion 18, the cutting tip 12 of the drill bit16 is cleaned immediately subsequent to the removal of the drill bit 16from within a drill bit container 26. Such cleaning is accomplished bymaneuvering the loader assembly 62 such that the shaft member 72, andmore particularly the fluted portion 14 of the drill bit 16 protrudingtherefrom, is vertically aligned with the cleaning putty 84 of one ofthe primary cleaning assemblies 80. Thereafter, the shaft member 72 ismoved downwardly along the third loader axis LA3 by the third armsegment 67 of the robotic arm so as to facilitate the insertion of thecutting tip 12 of the drill bit 16 into the quantity of cleaning putty84. The shaft member 72 is then moved upwardly along the third loaderaxis LA3 by the third arm segment 67 so as to facilitate the removal ofthe cutting tip 12 from within the cleaning putty 84. It will berecognized by those skilled in the art that alternative cleaning systemssuch as laser systems; carbon dioxide systems; fluidic bath systems andthe like are expressly contemplated herein.

[0082] As will be recognized, if the drill bit 16 has been grasped byone of the shaft members 72 of the gripper 70 in the manner shown inFIG. 4 (i.e., the shaft member 72 is advanced over the fluted portion 14of the drill bit 16), the drill bit 16 must be inverted to accomplishthe cleaning of the cutting tip 12 thereof via one of the primarycleaning assemblies 80. Such inversion is accomplished through the useof one of the inversion assemblies of the apparatus 10 as will bedescribed in more detail below.

[0083] Inversion Assemblies

[0084] Referring now to FIGS. 2, 3 and 5, the apparatus 10 of thepresent invention further includes a pair of identically configuredinversion assemblies 85 which, as will be discussed in more detailbelow, are each used to facilitate the selective inversion or flippingof a drill bit 16. The inversion assemblies 85 each comprise a basemember 86 which is attached to the top surface of the support plate 50.Rotatably connected to the base member 86 is an inversion arm 87 whichextends in a generally horizontal direction. The inversion arm 87 isrotatable relative to the base member 86 via a rotary actuator (notshown) disposed therewithin. Attached to the distal end of the inversionarm 87 is a holder block 88 having an aperture extending therethroughwhich is sized to have a diameter slightly exceeding that of thelocating ring 22 positioned upon a drill bit 16.

[0085] Each inversion assembly 85 further comprises an elongate lockingpin 89 which is movably attached to the base member 86 and defines adistal end which is reciprocally movable into and out of the apertureextending through the holder block 88. Also attached to the base member86 is an air stream generator 90 which is adapted to direct a highpressure air stream against the cutting tip 12 of a drill bit 16 forreasons which will be discussed in more detail below.

[0086] As indicated above, if the shaft member 72 of the gripper 70 hasinitially been advanced over the fluted portion 14 of a drill bit 16 andinto contact with the locating ring 22, the drill bit 16 must beinverted via one of the inversion assemblies 85 to allow the cutting tip12 thereof to be initially cleaned by one of the primary cleaningassemblies 80. Such inversion is accomplished by maneuvering the shaftmember 72 via the robotic arm of the loader assembly 62 such that theshank portion 18 of the drill bit 16 protruding therefrom is coaxiallyaligned with the aperture extending through the holder block 88 of oneof the inversion assemblies 85. Thereafter, the shaft member 72 is moveddownwardly by the third arm segment 67 of the robotic arm along thethird loader axis LA3 so as to facilitate the insertion of the shankportion 18 into the aperture of the holder block 88.

[0087] After the drill bit 16 has been inserted into the holder block88, the operation of the inversion assembly 85 is initiated by theactuation of the locking pin 89 so as to cause the same to move intoengagement with the shank portion 18 of the drill bit 16. As will berecognized, the engagement of the distal end of the locking pin 89 tothe shank portion 18 effectively locks the drill bit 16 within theholder block 88. The equalization of the pressure level within the shaftmember 72 and retraction thereof from the drill bit 16 (i.e., upwardmovement of the shaft member 72 along the third loader axis LA3) occurssubsequent to the engagement of the locking pin 89 to the shank portion18 of the drill bit 16.

[0088] As will be recognized, subsequent to the locking of the drill bit16 within the holder block 88 and retraction of the gripper 70therefrom, the fluted portion 14 of the drill bit 16 projects generallyvertically upwardly. Thereafter, the inversion arm 87 of the inversionassembly 85 is rotated approximately 180° by the rotary actuator so asto cause the shank portion 18 of the drill bit 16 to be directedgenerally vertically upwardly. Subsequent to such inversion, the roboticarm of the loader assembly 62 is used to maneuver one of the shaftmembers 72 of the gripper 70 such that the aperture 74 thereof iscoaxially aligned with the shank portion 18 of the drill bit 16. Theshaft member 72 is then moved downwardly along the third loader axis LA3by the third arm segment 67 and advanced over the shank portion 18 ofthe drill bit 16. Upon the creation of a vacuum within the aperture 74sufficient to maintain the drill bit 16 therewithin, the locking pin 89of the inversion assembly 85 is retracted so as to remove the distal endthereof from its engagement to the shank portion 18. Such disengagementallows the drill bit 16 to be removed from within the holder block 88 bythe upward movement of the shaft member 72 along the third loader axisLA3. As will be recognized, upon the removal of the drill bit 16 fromwithin the holder block 88, the fluted portion 14 of the drill bit 16protrudes from the shaft member 72, thus allowing the cutting tip 12 tobe cleaned via one of the primary cleaning assemblies 80 in theabove-described manner.

[0089] In the apparatus 10 of the present invention, each drill bit 16must be inverted via one of the inversion assemblies 85 subsequent tothe cutting tip 12 thereof being cleaned via one of the primary cleaningassemblies 80 in the above-described manner. In this respect, after thecutting tip 12 has been initially cleaned, the drill bit 16 must begrasped by the gripper 70 of the loader assembly 62 such that the shankportion 18 rather than the fluted portion 14 protrudes from one of theshaft members 72.

[0090] The inversion process following the initial cleaning of thecutting tip 12 is accomplished by maneuvering the shaft member 72 havingthe just cleaned drill bit 16 therewithin such that the fluted portion14 of the drill bit 16 is coaxially aligned with the aperture extendingthrough the holder block 88 of one of the inversion assemblies 85.Thereafter, the shaft member 72 is moved downwardly along the thirdloader axis LA3 by the third arm segment 67 of the robotic arm so as tofacilitate the insertion of the fluted portion 14 into the aperture ofthe holder block 88. After the fluted portion 14 has been advancedthrough the aperture of the holder block 88, the locking pin 89 isactuated so as to cause the distal end thereof to extend into engagementwith the shank portion 18 of the drill bit 16. As explained above, theengagement of the distal end of the locking pin 89 to the shank portion18 effectively locks the drill bit 16 within the holder block 88. Theshaft member 72 is then moved upwardly along the third loader axis LA3by the third arm segment 67 so as to retract the same from the drill bit16.

[0091] As will be recognized, when the drill bit 16 is locked within theholder block 18 and gripper 70 of the loader assembly 62 retractedtherefrom, the shank portion 18 is directed generally verticallyupwardly, with the fluted portion 14 being directed generally verticallydownwardly. The air stream generator 90 of the inversion assembly 85 isthen activated, and is caused to direct a high pressure air streamagainst the cutting tip 12 of the drill bit 16 in the manner shown inFIG. 5. Importantly, the impingement of air against the cutting tip 12effectively removes any residual cleaning putty therefrom. Thereafter,the inversion arm 87 of the inversion assembly 85 is rotatedapproximately 180° so as to cause the fluted portion 14 to be directedgenerally vertically upwardly.

[0092] Subsequent to the inversion of the drill bit 16, one of the shaftmembers 72 of the gripper 70 is maneuvered such that the aperture 74thereof is coaxially aligned with the fluted portion 14. The shaftmember 72 is then moved downwardly along the third loader axis LA3 viathe third arm segment 67 of the robotic arm and advanced over the flutedportion 14. The vacuum is then created within the aperture 74 at a levelsufficient to maintain the drill bit 16 therewithin. Thereafter, thelocking pin 89 of the inversion assembly 85 is retracted or disengagedfrom the shank portion 18, thus allowing the drill bit 16 to be removedfrom within the holder block 88 by the upward movement of the shaftmember 72 along the third loader axis LA3 by the third arm segment 67 ofthe robotic arm. As will be recognized, upon the removal of the drillbit 16 from the inversion assembly 85, the shank portion 18 thereofprotrudes from one of the shaft members 72 of the gripper 70.

[0093] Workhead Assemblies

[0094] Referring now to FIGS. 2, 3, 6 and 6 a, the apparatus 10 furthercomprises an identically configured pair of workhead assemblies 96, eachof which is used to transport a drill bit 16 between other assemblies ofthe apparatus 10 as will be described in more detail below. Each of theworkhead assemblies 96 comprises a generally rectangular base member 98which is reciprocally moveable along a base member axis BX (as shown inFIG. 3). The base member axes BX of the workhead assemblies 96 extend inco-planar, parallel relation to each other.

[0095] The movement of the base member 98 along its base member axis BXis facilitated by an actuator 100 of the workhead assembly 96. As bestseen in FIG. 2, the actuator 100 of each workhead assembly 96 preferablycomprises a pneumatic cylinder, the body of which is attached to the topsurface 44 of the housing 42 and disposed underneath a respective one ofthe cassette trays 54. Extending axially from the body is an elongatepiston rod, the distal end of which is attached to the base member 98.As will be recognized, the advancement of the piston rod of the actuator100 from within the body thereof results in the movement of the basemember 98 along its base member axis BX away from the cassette trays 54.Conversely, the retraction of the piston rod of the actuator 100 intothe body thereof results in the movement of the base member 98 along itsbase member axis BX toward the cassette trays 54. Those of ordinaryskill in the art will recognize that the actuator 100 used to facilitatethe movement of the base member 98 along its base member axis BX maycomprise devices other than for a pneumatic cylinder.

[0096] In addition to the base member 98 and actuator 100, each workheadassembly 96 comprises a swivel member 102 having a swivel member housing103 which is rotatably connected to the base member 98 via a bearing101. The swivel member 102 is rotatable about a swivel member axis whichextends in generally perpendicular relation to the base member axis BX,and thus extends in generally parallel relation to the first, second andthird loader axis LA1, LA2, LA3. The rotation of the swivel member 102relative to the base member 98 is accomplished by the selectiveactivation of a first stepper motor 104 thereof which extends from theswivel member housing 103. The rotation of the swivel member 102relative to the base member 98 may alternatively be accomplished throughthe use of a pneumatic cylinder rather than the first stepper motor 104.

[0097] Each workhead assembly 96 further comprises a collet member 106which is attached to the swivel member 102. The collet member 106includes a collet member housing 107 having a cylindrically configuredcollet shaft 108 extending therefrom. Attached to the distal end of thecollet shaft 108 is a locking sleeve 111 which accommodates a collethead 110. In the workhead assembly 96, the collet shaft 108, and hencethe collet head 110, is reciprocally movable relative the collet memberhousing 107 along a collet axis CX (shown in FIG. 6). In addition tobeing movable along the collet axis CX, the collet shaft 108 isrotatable thereabout. The movement of the collet shaft 108 along andabout the collet axis CX is facilitated by a second stepper motor 112 ofthe collet member 106 which extends from the collet member housing 107thereof. The collet axis CX extends in generally parallel relation tothe plane of the top surface 44 of the housing 42 throughout therotation of the swivel member 102. The first and second stepper motors104, 112 may comprise servo motors, or linear servo motors. Since thesecond stepper motor 112 facilitates the rotation of the collet shaft108 about the collet axis CX, such motor provides a prescribedrotational positioning of the cutting tip 12 of the drill bit 16 as willbe described in more detail below.

[0098] Referring now to FIGS. 4, 4a, 6 and 6 a, in the apparatus 10, adrill bit 16 is insertable into and removable from within the collethead 110 of each workhead assembly 96 by the loader assembly 62. In thisrespect, the collet head 110 is sized and configured to slidably receivethe shank portion 18 of a drill bit 16, with the advancement of theshank portion 18 into the collet head 110 being limited by a stopperwithin the collet head 110 which is adjusted so that only aboutone-eighth of an inch of the shank portion 18 of the drill bit 16 isinserted into and locked within the collet head 110. Since the colletaxis CX extends horizontally, a drill bit 16 held vertically within ashaft member 72 of the gripper 70 in the above-described manner must bepivoted to extend along the gripper axis GX (as shown in FIG. 4a) priorto being insertable into the collet head 110. In addition to the shaftmember 72 being pivoted by the actuator member 78 to facilitate theextension of the drill bit 16 along the gripper axis GX, the shaftmember 72 must also be maneuvered by the loader assembly 62 such thatthe gripper axis GX is coaxially aligned with the collet axis CX inorder for the shank portion 18 to be insertable into the collet head110. The gripper axis GX must also be coaxially aligned with the colletaxis CX for the shaft member 72 to be advanced over the fluted portion14 of the drill bit 16 and into contact with the locating ring 22 tofacilitate the removal of the drill bit 16 from within the collet head110.

[0099] As best seen in FIG. 6, each workhead assembly 96 furthercomprises an elongate support member 114 which is attached to the basemember 98. Extending through the support member 14 in close proximity tothe top end thereof is an aperture 116 which is sized and configured toslidably receive the locking sleeve 111. As will be described in moredetail below, the locking sleeve 111 is slidably advanced into theaperture 116 as part of the process of re-sharpening the cutting tip 12of the drill bit 16 so as to allow the support member 14 to guide andprevent excessive vibration of the drill bit 16 within the collet head110 during the re-sharpening process.

[0100] Optical Assemblies

[0101] Referring now to FIGS. 2, 3 and 7, the apparatus 10 furthercomprises a pair of vision or optical assemblies 118, each of which isadapted to generate images preferably digital images used to verify theidentity and geometry of the drill bit as well as conduct initial andfinal inspections or evaluations of the cutting tip 12 and flutedportion 14 of a drill bit 16 inserted thereinto, as will be described inmore detail below. The optical assemblies 118 are each attached to thetop surface 44 of the housing 42 and are disposed under respective onesof the cassette trays 54.

[0102] As best seen in FIG. 7, each of the optical assemblies 118comprises an optical housing 120 having a circularly configured opening122 disposed within one of the sidewalls thereof. The opening 122 issized and configured to receive the locking sleeve 111 of one of theworkhead assemblies 96. When the optical assemblies 118 are mounted tothe housing 42, the distance separating the opening 122 of each opticalhousing 120 from the top surface 44 of the housing 42 is such that thecollet axis CX of one of the workhead assemblies 96 may be coaxiallyaligned with the opening 122. Such alignment is needed to allow a drillbit 16 held within the collet head 110 of a workhead assembly 96 to beinsertable into the interior of the optical housing 120 via the opening122 upon the movement of the base member 98 of the workhead assembly 96along the base member axis BX.

[0103] Disposed within the interior of the optical housing 120 is acircularly configured illumination ring or array 124 which is coaxiallyaligned with the opening 122. The illumination array 124 preferablycomprises a sequential ring of LED's which emit red light. Attached tothe sidewall of the optical housing 120 opposite that including theopening 122 disposed therein is a front camera 126 of the opticalassembly 118. The front camera 126 protrudes into the interior of theoptical housing 120, and includes a circularly configured lens which iscoaxially aligned with both the opening 122 and the illumination array124. In addition to the front camera 126, each optical assembly 118includes a top camera 128 which is attached to the top of the opticalhousing 120. Like the front camera 126, the top camera 128 protrudesinto the interior of the optical housing 120, and includes a circularlyconfigured lens which extends in generally perpendicular relation to thecollet axis CX when a drill bit 16 is inserted into the interior of theoptical housing 120 by a workhead assembly 96. Although various opticalsystems are contemplated herein, a preferred system is manufactured byVolution, Inc. of San Diego, Calif.

[0104] Grinding Assemblies

[0105] Referring now to FIGS. 2, 3 and 8, the apparatus 10 furthercomprises a pair of grinding assemblies 130 which are attached to thetop surface 44 of the housing 42. Each of the grinding assemblies 130comprises a grinder mount 132 which has a generally U-shapedconfiguration. Movably attached to the grinder mount 132 and disposedbetween the end portions defined thereby are first and second grindermotors 134, 136. Rotatably connected to the first grinder motor 134 is afirst circularly configured grinding head 138, while rotatably connectedto the second grinder motor 136 is a second circularly configuredgrinder head 140.

[0106] In the apparatus 10, the grinding faces of the first and secondgrinder heads 138, 140 typically do not extend in perpendicular relationto the top surface 44 of the housing 42, but rather are angularlyoff-set relative thereto. In each grinding assembly 130, the angularorientations of the grinding faces of the first and second grinder heads138, 140 relative to the top surface 44 may be selectively adjusted. Inthis respect, the grinder mount 132 includes a pair of accurately shapedslots 142 disposed within respective ones of the end portions definedthereby. The attachment of the first and second grinder motors 134, 136to the grinder mount 132 is facilitated by the receipt of mountingshafts extending from each of the first and second grinder motors 134,136 into respective ones of the slots 142. The tightening of a clampingmember 144 disposed on the distal end of at least one of the mountingshafts maintains the mounting shafts in a desired location within theslots 142. As will be recognized, the loosening of the clamping member144 allows the location of the mounting shafts within the slots 142 tobe selectively adjusted as needed to alter the angular orientations ofthe grinding faces of the first and second grinder heads 138, 140relative to the top surface 44 of the housing 42. In each grindingassembly 130, the first and second grinder motors 134, 136 areinterconnected, and thus move in unison when the angular orientations ofthe grinding faces of the first and second grinder heads 138, 140 areadjusted in the above-described manner.

[0107] Referring now FIG. 13, each of the grinding assemblies 130 of theapparatus 10 may be optionally outfitted with a pair of adjustmentmechanisms 300. Each of the adjustment mechanisms 300 comprises ahousing 302 which has a generally rectangular configuration and definesa hollow interior. Extending longitudinally through the hollow interiorof the housing 302 is an elongate ball screw 304 which is rotatablymounted within each of the opposed, lateral sidewalls of the housing302. Mechanically coupled to one end of the ball screw 304 is a steppermotor 306 which is itself mounted to the outer surface of one of thelateral sidewalls of the housing 302. The stepper motor 306, whenactivated, is operative to selectively rotate the ball screw 304 ineither a first direction or a second direction which is opposite thefirst direction.

[0108] Each adjustment mechanism 300 further comprises a linear bearing308 which has a generally rectangular configuration and includes acantilever member 310 mounted to one of the opposed lateral sidesthereof. The cantilever member 310 is itself cooperatively engaged tothe ball screw 304 via a ball nut 312 disposed on the end thereofopposite that attached to the linear bearing 308. As shown in FIG. 13,mounted to the outer surface of the linear bearing 308 is the firstgrinder motor 134. Extending from the first grinder motor 134 is a firstrotatable motor shaft 135 which includes the first grinder head 138attached to the distal end thereof. As will be recognized, the firstmotor shaft 135 facilitates the rotatable connection of the firstgrinder head 138 to the first grinder motor 134.

[0109] Due to the mounting of the first grinder motor 134 to the linearbearing 308, the activation of the stepper motor 306 is operative toselectively move the first grinder motor 134, and hence the firstgrinder head 138, back and forth along the grinder head axis GH shown inFIG. 13. In this respect, the rotation of the ball screw 34 in the firstdirection facilitates the movement of the first grinder head 138 alongthe grinder head axis GH in a direction away from the stepper motor 306.Conversely, the rotation of the ball screw 304 in the second directionopposite the first direction facilitates the movement of the firstgrinder head 138 along the grinder head axis GH in a directon toward thestepper motor 306. The advantages attendant to the ability to move thefirst grinder head 138 back and forth along the grinder head axis GHwill be discussed in more detail below. Though not shown, the adjustmentmechanism 300 may further include a spring which is disposed within theinterior of the housing 302 and cooperatively engaged to the linearbearing 308 for purposes of applying a pre-load thereto.

[0110] As will be recognized, in the alternative grinding assembly 130including the adjustment mechanisms 300, the second grinder motor 136 ismounted to the outer surface of the linear bearing 308 of the other,remaining adjustment mechanism 300. The adjustment mechanisms 300, andin particular the housings 300 thereof, may be attached to a modifiedversion of the grinder mount 132 which is sized and configured toaccommodate the same.

[0111] Secondary Cleaning Assemblies

[0112] Referring now to FIGS. 2, 3 and 8 a, the apparatus 10 furthercomprises a pair of secondary cleaning assemblies 180 which are attachedto the top surface 44 of the housing 42 outwardly of respective ones ofthe cassette trays 54. The secondary cleaning assemblies 180 are used tofacilitate the cleaning of the cutting tip 12 of a drill bit 16 prior tothe final inspection thereof by one of the optical assemblies 118 aswill be described in more detail below.

[0113] Each of the secondary cleaning assemblies 180 comprises a basemember 182 which is attached to the top surface 44 of the housing 42.Movably attached to the base member 182 is an elongate conveyor bar 184which includes a pair of conveyor rollers 186 rotatably connected to acommon side thereof in relative close proximity to respective ones ofthe opposed ends thereof. Attached to one of the conveyor rollers 186 isan indexing wheel 188, while extending about the conveyor rollers 186 isa continuous conveyor belt 190. Additionally, attached to the basemember 182 is an indexing member 192 which extends upwardly toward theindexing wheel 188. As seen in FIG. 8a, the conveyor belt 190 isprovided with quantities of cleaning putty 194 thereon, with each suchquantity of cleaning putty 194 being disposed between a respective pairof ribs formed on the conveyor belt 190.

[0114] In each secondary cleaning assembly 180, the base member 182 isoperable to selectively actuate the conveyor bar 184, and hence theconveyor belt 190, between a retracted position as shown in FIG. 8a andan extended position as shown in phantom in FIG. 8a. When the conveyorbelt 190 is in the extended position, one of the quantities of cleaningputty 194 disposed thereon is in general horizontal alignment with theaxis of the opening 122 of a respective one of the optical assemblies118. When the conveyor belt 190 is in its retracted position, thequantities of cleaning putty 194 disposed thereon are orientedsubstantially below the axis of the opening 122. Importantly, themovement of the conveyor belt 190 from its extended position to itsretracted position results in the engagement of the distal end of theindexing member 192 to the indexing wheel 188 in a manner facilitatingthe indexing of the conveyor belt 190 a prescribed incremental distance.This movement of the conveyor belt 190 effectively places a successivequantity of cleaning putty 194 into horizontal alignment with the colletaxis CX when the same is coaxially aligned with the opening 122 of theassociated optical assembly 118.

[0115] Bumping Assembly

[0116] Referring now to FIGS. 2, 3 and 9, the apparatus 10 furthercomprises a bumping assembly 146 which is attached to the top surface 44of the housing 42 substantially intermediate the cassette trays 54. Thebumping assembly 146 is used to facilitate the re-positioning of thelocating ring 22 upon a drill bit 16 if needed subsequent to thecompletion of the re-sharpening of the cutting tip 12 of the drill bit16. The complete structure and manner of operation of the bumpingassembly 146 is described in detail in U.S. Pat. No. 5,472,298 entitledLOCATING RING POSITIONING APPARATUS FOR RE-SHARPENED DRILL BIT issuedDec. 5, 1995, the entire disclosure of which is incorporated herein byreference.

[0117] The bumping assembly 146 generally comprises a drill seat oranvil 148 which is attached to the top surface 44 of the housing 42.Extending axially through the drill seat 148 is an aperture 150 forslidably receiving the shank portion 18 of a drill bit 16. The diameterof the aperture 150 is sized so as to slightly exceed the diameter ofthe shank portion 18, thus facilitating the slidable receipt of theshank portion 18 thereinto. In addition to the drill seat 148, thebumping assembly 146 has a reciprocal ram or hammer assembly whichincludes an enlarged tool head 152. The tool head 152 defines a centralaperture 154 extending axially therethrough which is slightly larger indiameter than the aperture 150 extending axially through the drill seat148. The central aperture 154 of the tool head 152 is coaxially alignedwith the aperture 150, and thus in coaxial alignment with thelongitudinal axis of a drill bit 16 inserted into the drill seat 148.

[0118] As seen in FIG. 9, the distal portion of the central aperture 154is enlarged in size to partially receive the locating ring 22 positionedupon a drill bit 16. In this respect, the diameter of the enlargedportion slightly exceeds the diameter of the locating ring 22, with thedepth D2 of the enlarged portion being slightly less than the width W1of the locating ring 22. As further seen in FIG. 9, the enlargement ofthe distal portion of the central aperture 154 facilitates the formationof an annular bumping surface 156 which circumvents the reduced diameterportion of the central aperture 154, and is adapted to contact thelocating ring 22. As will be described in more detail below, when adrill bit 16 is inserted into the drill seat 148 and the ram assembly isactuated to facilitate the downward movement of the tool head 152, thecutting tip 12, fluted portion 14, tapered region 20 and upper end ofthe shank portion 18 of the drill bit 16 are received into the centralaperture 154, with the locating ring 22 being “bumped” by the bumpingsurface 156 so as to force the locating ring 22 into abutting contactwith the top surface 158 of the drill seat 148.

[0119] The bumping assembly 146 further comprises an adjustmentmechanism for positioning the cutting tip 12 of a drill bit 16 insertedinto the drill seat 148 at a desired separation distance SD from the topsurface 158 of the drill seat 148. The adjustment mechanism includes anoptical reference system which is adapted to produce a laser beam Lwhich travels perpendicularly relative the longitudinal axis of thedrill bit 16 and is spaced from the top surface 158 of the drill seat148 by the separation distance SD. In addition to the optical referencesystem, the adjustment mechanism comprises a reversible linear actuatoror stepper motor which is disposed within the interior of the housing 42and includes an elongate lead screw 160 which is selectively extensiblefrom and retractable into the stepper motor. Extending axially from thetop end of the lead screw 160 is an elongate, cylindrically configuredpin portion 162 which defines a blunt distal end. The diameter of thepin portion 162 is slightly less than the diameter of the aperture 150,thus allowing the pin portion 162 to be slidably extensible into theaperture 150 and vertically moveable therewithin.

[0120] In the apparatus 10, the bumping assembly 146 is utilized byinitially inserting the shank portion 18 of a drill bit 16 into theaperture 150 of the drill seat 148 via the loader assembly 62. Theinsertion of the shank portion 18 into the aperture 150 is limited bythe abutment of the end 24 thereof against the distal end of the pinportion 162 which, as previously indicated, resides within the aperture150.

[0121] Subsequent to the insertion of the drill bit 16 into the drillseat 148, the optical laser beam L is transmitted horizontally, and moreparticularly perpendicularly relative the longitudinal axis of the drillbit 16 inserted into the drill seat 148. The laser beam L is oriented soas to be separated from the top surface 158 of the drill seat 148 by theseparation distance SD which is preferably the sum of the distance D1and the width W1 of the locating ring 22. When the drill bit 16 isinitially inserted into the drill seat 148, the cutting tip 12 istypically disposed above the level of the laser beam L. As such, sincethe cutting tip 12 must be positioned at the separation distance SDprior to bumping the locating ring 22, the drill bit 16 must typicallybe lowered within the drill seat 148 so as to precisely position thecutting top 12 within the laser beam L.

[0122] The lowering of the drill bit 16 within the drill seat 148 isaccomplished by activating the stepper motor in a manner causing thelead screw 160 to move in a downward vertical direction, which in turncauses the distal end of the pin portion 162 to move downwardly withinthe aperture 150. Since the bottom end 24 of the shank portion 18 isabutted against the pin portion 162 when the drill bit 16 is initiallyinserted into the drill seat 148, the downward movement of the pinportion 162 causes the shank portion 18 to be retracted into the drillseat 148, thus lowering the level of the cutting tip 12.

[0123] The downward vertical movement of the lead screw 160 is continuedto such time as the cutting tip 12 is disposed below the laser beam L.When it is determined that the cutting tip 12 is disposed below thelevel of the laser beam L (i.e., a continuous laser beam L istransmitted and uninterrupted by the cutting tip 12), the stepper motoris deactivated and the downward vertical movement of the lead screw 160stopped. Thereafter, the stepper motor is re-energized in a mannerfacilitating the upward vertical movement of the lead screw 160 and pinportion 162 thereof. The upward movement of the lead screw 160facilitates the simultaneous upward movement of the cutting tip 12toward the laser beam L. At the precise moment the cutting tip 12interrupts the laser beam L, the stepper motor is deactivated, thusresulting in the cutting tip 12 being spaced from the top surface 158 ofthe drill seat 148 by the separation distance SD.

[0124] When the cutting tip 12 is positioned within the laser beam L andthus spaced from the top surface 158 by the separation distance SD, aslight gap will typically be defined between the locating ring 22 andthe top surface 158 of the drill seat 148. Thereafter, the ram assemblyis actuated to facilitate the rapid downward movement of the tool head152. As previously indicated, the downward actuation of the tool head152 results in the locating ring 22 being contacted or “bumped” by thebumping surface 156 defined about the central aperture 154. Importantly,the bumping of the locating ring 22 by the tool head 152 overcomes thefrictional or press-fit engagement of the locating ring 22 upon theshank portion 18 of the drill bit 16 and forces the locating ring 22downwardly into abutting contact with the top surface 158 of the drillseat 148. Once the locating ring 22 is abutted against the top surface158, it is spaced from the cutting tip 12 at the desired distance D1.The locating ring 22 is preferably bumped twice by the tool head 152,with the first bump being utilized to force the locating ring 22 inabutting contact with the top surface 158, and the second bump beingutilized to jettison any residual flash or debris from the locating ring22.

[0125] As seen in FIGS. 2 and 3, the ram assembly of the bumpingassembly 146 is movably mounted to a base carriage 164 of the bumpingassembly 146 and linearly moveable between extended and retractedpositions relative to the drill seat 148. When the ram assembly is inits extended position, the central aperture 154 of the tool head 152 iscoaxially aligned with the aperture 150 of the drill seat 148.Conversely, when the ram assembly is actuated to its retracted position(as shown in FIGS. 2 and 3), the same is spaced horizontally away fromthe drill seat 148, thus providing access to the aperture 150 to allowthe loader assembly 62 to insert the drill bit 16 thereinto in theabove-described manner.

[0126] Apparatus Operation

[0127] Having thus described the various assemblies of the apparatus 10,the operation thereof will now be explained with reference to FIGS.11a-11 n. In the apparatus 10, the programmable control device(s)disposed within either or both of the control panels 46 or within theinterior of the housing 42 functions to control and coordinate theoperations of the loader assembly 62, inversion assemblies 85, workheadassemblies 96, optical assemblies 118, grinding assemblies 130,secondary cleaning assemblies 180, and bumping assembly 146. In thisrespect, the control device is electrically interfaced to the variouscomponents of these assemblies (e.g., first and second stepper motors104, 112, front and top cameras 126, 128, first and second grindermotors 134, 136), and to auxiliary control devices such as solenoidvalves, cylinders and the vacuum pump which are used to facilitate thecontrol of other components of the assemblies.

[0128] In the following discussion of the operation of the apparatus 10,the sequence of steps will be described in relation to the re-sharpeningof the cutting tip 12 of a drill bit 16 and the re-positioning of thelocating ring 22 thereof through the use of one of the cassette trays54, the loader assembly 62, one of the shaft members 72 of the gripper70, one of the primary cleaning assemblies 80, one of the inversionassemblies 85, one of the workhead assemblies 96, one of the opticalassemblies 118, one of the grinding assemblies 130, one of the secondarycleaning assemblies 180, and the bumping assembly 146. However, those ofordinary skill in the art will recognize that since the apparatus 10includes pairs of primary cleaning, workhead, optical, grinding andsecondary cleaning assemblies as well as a pair of shaft members 72 onthe gripper 70 and a pair of cassette trays 54, the cutting tipre-sharpening and locating ring re-positioning processes as willhereinafter be described may be conducted simultaneously on at least twodrill bits 16, with the control device being specifically adapted tocontrol and coordinate such simultaneous operations.

[0129] In using the apparatus 10, a drill bit container 26 including aplurality of drill bits 16 stored therewithin is positioned within anopening 56 of a cassette tray 54, with the cover 30 of the drill bitcontainer 26 being moved to its opened position or removed from the base28, thus exposing the fluted portions 14 of the drill bits 16 (FIG.11a). Thereafter, a single drill bit 16 is lifted out of the drill bitcontainer 26 by the loader assembly 62, and in particular a shaft member72 of the gripper 70 (FIG. 11b). The manner in which the loader assembly62 functions to grasp and release a drill bit 16 is described above inthe section captioned Loader Assembly. As will be recognized, thecontrol device of the apparatus 10 is programmed in a manner whichallows the same to maneuver a shaft member 72 of the gripper 70 intoaxial alignment with any drill bit 16 in a drill bit container 26 storedwithin any opening 56 of a cassette tray 54.

[0130] After being lifted out of the drill bit container 26, whennecessary, the drill bit 16 is transported by the loader assembly 62 toan inversion assembly 85, and is inserted by the loader assembly 62 intothe holder block 88 of the inversion arm 87 such that the fluted portion14 is directed generally vertically upwardly (FIG. 11c). The insertionof the drill bit 16 into the holder block 88 is accomplished in themanner previously described in the section captioned InversionAssemblies. After the drill bit 16 has been inserted into the holderblock 88 and the locking pin 89 extended so as to engage the shankportion 18 and lock the drill bit 16 within the holder block 88, theinversion arm 87 is rotated approximately 180° such that the shankportion 18 of the drill bit 16 is directed generally verticallyupwardly. The drill bit 16 is then removed from within the holder block88 by the loader assembly 62 in the manner also previously described inthe section captioned Inversion Assemblies.

[0131] After the drill bit 16 has been removed from within the holderblock 88 of an inversion assembly 85, the drill bit is transported bythe loader assembly 62 to a primary cleaning assembly 80, with thecutting tip 12 then being inserted into and removed from within thecleaning putty 84 via the loader assembly 62 to facilitate the cleaningthereof in the manner previously described in the section captionedPrimary Cleaning Assemblies. The drill bit is then transported back toan inversion assembly 85 and inserted by the loader assembly 62 into theholder block 88 such that the shank portion 18 is directed generallyvertically upwardly. Once again, the insertion of the drill bit 16 intothe holder block 88 is accomplished in the manner previously describedin the section captioned Inversion Assemblies. After the drill bit 16has been inserted into the holder block 88 and the locking pin 89extended so as to engage the shank portion 18 and lock the drill bit 16within the holder block 88, the inversion arm 87 is rotatedapproximately 180°, such that the fluted portion 14 is directedgenerally vertically upwardly. The drill bit 16 is then re-grasped bythe loader assembly 62 and removed from within the holder block 88 ofthe inversion assembly 85 (FIG. 11e) in the manner previously describedin the section captioned Inversion Assemblies.

[0132] As previously explained, if the drill bit 16 is initiallyoriented within the drill bit container 26 such that the shank portion18 rather than the fluted portion 14 thereof is directed generallyvertically upwardly, the step of inverting or flipping the drill bit 16prior to the initial cleaning of the cutting tip 12 thereof as shown anddescribed in relation to FIG. 11c is eliminated since the fluted portion14 (as opposed to the shank portion 18) already protrudes from the shaftmember 72. In this respect, the operational sequence of the apparatus 10proceeds directly from the removal of the drill bit 16 from within thedrill bit container 26 as shown and described in relation to FIG. 11b tothe cleaning of the cutting tip 12 in the manner shown and described inrelation to FIG. 11d. The inversion step conducted subsequent to theinitial cleaning of the cutting tip 12 as shown and described inrelation to FIG. 11e must always be completed irrespective of theinitial orientation of the drill bit 16 within the drill bit container26.

[0133] After the drill bit 16 has been lifted out of the holder block88, the actuator member 78 of the gripper 70 is activated so as torotate the shaft members 72 upwardly in a manner causing the drill bit16 to extend along the gripper axis GX (FIGS. 4a and 11 f). The loaderassembly 62 is then maneuvered so as to axially align the gripper axisGX with the collet axis CX of a workhead assembly 96. Subsequent to suchalignment, the shank portion 18 of the drill bit 16 is horizontallyadvanced into the collet head 110 of the collet member 106 of theworkhead assembly 96 and locked therein (FIG. 11g).

[0134] When the drill bit 16 is initially inserted into the collet head110, the orientation of the swivel member 102 and hence the colletmember 106 of the workhead assembly 96 is such that the collet axis CXis; coaxially aligned with the opening 122 within the optical housing120 of an optical assembly 118. The actuator 100 of the workheadassembly 96 is then activated to cause the retraction of the piston rodinto the body, thus resulting in the movement of the base member 98 ofthe workhead assembly 96 along the base member axis BX toward theoptical assembly 118. Such movement is continued until such time as thefluted portion 14 and cutting tip 12 of the drill bit 16 are properlypositioned within the interior of the optical housing 120 of the opticalassembly 118 (FIGS. 7 and 11h).

[0135] Referring now to FIGS. 7a-7 d, the movement of the drill bit 16into the optical assembly 118 causes the control device to trigger theperformance of a verification of the identity and geometry of the drillbit 16 and the initial inspection or evaluation of the fluted portion 14and cutting tip 12 by the optical assembly 118. As will discussed inmore detail below, the optical assembly 118 is provided with controllogic having unique operative capabilities in relation to the inspectionor evaluation and measurement of the cutting tip 12 of the drill bit 16.In the apparatus 10, each optical assembly 118 is in electricalcommunication with the control device for purposes of transmitting datapertaining to such evaluations and measurements thereto so as to providethe apparatus 10 of the present invention with statistical processcontrol (SPC) capability. The electrical communication between thecontrol logic of the optical assembly 118 and the control device of theapparatus 10 also allows for the selective activation and deactivationof the actuator 100 and first and second stepper motors 104, 112 of thecorresponding workhead assembly 96 as is needed to facilitate theindexing of the cutting tip 12 within the optical assembly 118 in aprescribed manner which will also be discussed in more detail below.

[0136] Referring now FIG. 7a, during the set-up of the apparatus 10, theoverall length (OAL) of the drill bit 16 as new is known and programmedor inputted into the control device. As the cutting tip 12 and flutedportion 14 of the drill bit 16 are being advanced into the interior ofthe optical assembly 118, the top camera 128 thereof begins generatingimages of the cutting tip 12 and the fluted portion 14 for purposes ofallowing the same to be oriented in a prescribed manner relative tovarious reference points established by the control logic of the opticalassembly 118. More particularly, as seen FIGS. 7a-7 d, the control logicof the optical assembly 118 is operative to produce a first set ofcross-hairs consisting of a first reference axis RA1 and a secondreference axis RA2 which extend perpendicularly relative to each otherand are superimposed on the images generated by the top camera 128. Asseen in FIGS. 7a and 7 c, the first set of cross-hairs are generated bythe control logic of the optical assembly 118 such that the secondreference axis RA2 extends in parallel relation to the collet axis CX.Thus, as the drill bit 16 is advanced into the optical assembly 118, thecutting tip 12 is advanced along the second reference axis RA2.

[0137] As indicated above, the overall length of a new drill bit 16 isknown and inputted into the control device of the apparatus 10. When thedrill bit 16 is initially advanced into the optical assembly 118, thecontrol device, using the data transmitted thereto from the opticalassembly 118, is operative to continue the movement of the base member98 of the workhead assembly 96 along the base member axis BX until suchtime as the chisel edge 200 of the cutting tip 12 of a new drill bit 16would be disposed at the point at which the first and second referenceaxes RA1, RA2 intersect. However, as seen in FIG. 7a, since theapparatus 10 is adapted for use in re-sharpening drill bits, the drillbit 16 advanced into the optical assembly 118, due to its prior usage,will typically not be of the same overall length as a new drill bit 16,but rather slightly shorter in length. Thus, when the movement of thework assembly 96 along the base member axis BX is stopped ordiscontinued, the chisel edge 200 of the cutting tip 12 will typicallyfall short of the intersection point between the first and secondreference axes RA1, RA2 due to the reduced length of the fluted portion14 attributable to the prior usage of the drill bit 16.

[0138] After the movement of the workhead assembly 96 has beendiscontinued, the control logic of the optical assembly 118 is operativeto measure or determine the distance DL separating the chisel edge 200of the cutting tip 12 from the intersection point between the first andsecond reference axes RA1, RA2. This distance DL as determined by theoptical assembly 118 is transmitted to the control device, thus allowingthe control device to calculate the actual overall length of the drillbit 16 within the optical assembly 118. The actual overall length isderived by subtracting the distance DL from the new drill lengthmeasurement previously input into the control device. The calculatedactual overall length of the drill bit 16 is stored within the controldevice of the apparatus 10. Subsequent to this calculation of theoverall length of the drill bit 16, the control device of the apparatus10 re-initiates the movement of the workhead assembly 96 along the basemember axis BX. More particularly, the workhead assembly 96 is caused tomove the drill bit 16 through the distance DL so as to place the chiseledge 200 of the cutting tip 12 at the intersection point of the firstand second reference axis RA1, RA2.

[0139] Referring now to FIG. 7b, after the cutting tip 12 of the drillbit 16 has been indexed forwardly by the control device in theabove-described manner, images of the cutting tip 12 of the drill bit 16are then generated by the front camera 126 of the optical assembly 118.The control logic of the optical assembly 118 is further operative togenerate a second set of cross-hairs consisting of a generallyhorizontal third reference axis RA3 and a generally vertical fourthreference axis RA4 which extend perpendicularly relative to each otherand are superimposed on the images generated by the front camera 126.The second set of cross-hairs are produced by the control logic of theoptical assembly 118 such that the intersection point between the thirdand fourth reference axis RA3, RA4 is oriented upon the collet axis CX.As is seen in FIG. 7b, the control logic of the optical assembly 118 isfurther operative to determine or measure the diameter D of the drillbit 16 through the use of the images generated by the front camera 126.The diameter D as determined by the control logic of the opticalassembly 118 is transmitted to and stored within the control device ofthe apparatus 10. Additionally, as seen in FIG. 7d, by using or focusingon the primary faces or facets 204 of the cutting tip 12, the controllogic of the optical assembly 118 is operative to establish a referenceline RL which extends generally along the straight sections of thecutting edges 202 of the cutting tip 12.

[0140] Subsequent to the establishment of the reference line RL, thecontrol logic of the optical assembly 118 is operative to determine ormeasure the angle A between the reference line RL and the thirdreference axis RA3 of the second set of cross-hairs. The measured angleA is transmitted to and stored within the control device along with themeasurement of the diameter D and previously calculated overall lengthof the drill bit 16. It is preferred that the angle A be less than 90degrees. If the angle A is determined to be outside of this desiredrange, the control device is operative to facilitate the rotation of thecollet shaft 108 and hence the collet head 110 via the second steppermotor 112, thus resulting in the rotation of the drill bit 16 relativeto the collet axis CX. The rotation of the drill bit 16 relative to thecollet axis CX is continued until it is determined by the control logicof the optical assembly 118 that the angle A is within the desiredrange. Once the angle A is within the desired range, the specificmeasurement thereof is transmitted to and stored within the controldevice.

[0141] Referring now to FIG. 7c, subsequent to the measurement of theangle A, images are once again generated by the top camera 128 of theoptical assembly 118. Based on these generated images, the control logicof the optical assembly 118 is operative to identify the margins of thedrill bit 16, and to establish or generate a target line TL whichextends generally along one of the margins and over the distal end oredge thereof defined at the cutting tip 12. In addition to the targetline TL being produced by the control logic of the optical assembly 118,the images generated by the top camera 128 are used to cause the controldevice to facilitate a slight incremental movement of the workheadassembly 96 along the base member axis BX. More particularly, the drillbit 16 is moved forwardly along the second reference axis RA2 until itis determined by the control logic of the optical assembly 118 that thefirst reference axis RA1 extends generally along the distal ends oredges of both margins of the drill bit 16. Thereafter, the controldevice is operative to facilitate the rotation of the collet shaft 108and hence the drill bit 16 relative to the collet axis CX, with suchrotation being continued until the target line TL crosses or intersectsthe point of intersection between the first and second reference axesRA1, RA2 of the first set of crosshairs. It is contemplated that inaddition to generating the target line TL relative to one of the marginsof the drill bit 16, the control logic of the optical assembly 118 willfurther be operative to conduct an initial evaluation of the conditionof the margins of the drill bit 16, and in particular the portionsthereof adjacent the cutting tip 12. Data corresponding to this initialevaluation will be transmitted to and stored within the control device.

[0142] As will be recognized, the rotation of the drill bit 16 tofacilitate the passage of the target line TL across the point ofintersection of the first and second references axes RA1, RA2 of thefirst set of cross-hairs will result in a change to the previouslymeasured angle A. However, the control device of the apparatus 10,working in conjunction with the control logic of the optical assembly118, is able to calculate the new angle A of the reference line RLrelative to the third reference axis RA3 resulting from the rotation ofthe drill bit 16 in accordance with the step shown in FIG. 7c. As isdiscussed below, the stored new angle A is used as a baseline setting tofacilitate the later adjustment of the angle A as is needed tofacilitate the proper engagement of the cutting tip 12 to the grindingassembly 130 and the proper illumination of the cutting 12 within theoptical assembly 118 during the final inspection or evaluation thereof.

[0143] The adjustments to the angular orientation of the cutting tip 12as may be used to establish the angle A in the desired range and/or theextension of the target line TL through the point of intersection of thefirst and second reference axis RA1, RA2 is preferably accomplishedthrough a first rough rotation of the collet shaft 108 of the workheadassembly 96, which is immediately followed a fine rotation thereof.Importantly, the workhead assembly 96, and more particularly the secondstepper motor 112 thereof, is operable to provide positional accuracy tothe angular orientation of the cutting tip 12 to within about 0.000005inches.

[0144] It is contemplated that if either the calculated overall lengthmeasurement of the drill bit 16 or the diameter D thereof is initiallydetermined to be outside of specified tolerances, the drill bit 16 willimmediately be rejected from further processing. Similarly, if theinitial evaluation of the margin condition of the drill bit 16demonstrates that one or both of the margins are outside of a prescribedtolerance, the drill bit 16 will be rejected from further processingwithin the apparatus 10. Thus, in the apparatus 10 of the presentinvention, the drill bit 16, and in particular the cutting tip thereof,is subjected to various initial qualifications, and is rejected prior toany re-grinding if such initial qualifications are not properlysatisfied. Thus, as indicated above, a parameter such the actual overalllength of the drill bit 16 may be used to determine whether the cuttingtip 12 thereof should be re-ground or whether the drill bit 16 should bethrown-out.

[0145] As explained above, the control logic of the optical assembly 118is operable to process and interpret the images generated by the frontand top cameras 126, 128. Due to the optical assembly 118 being inelectrical communication with the control device and operative totransmit data corresponding to the images generated by the front and topcameras 126, 128 thereto, the control device is able to regulate themovement of the workhead assembly 96 (i.e., the movement of the basemember 98 along the base member axis BX and/or the rotation of thecollet shaft 108 about the collet axis CX) in response to such data asis needed to accomplish the indexing and adjustment steps described inrelation to FIGS. 7a-7 d. As also indicated above, the data obtainedfrom the initial evaluation of the drill bit 16 (i.e., the overalllength, diameter D, angle A and margin condition) is stored within thecontrol device for future reference and for purposes of updating theartificial intelligence of the control device. During the initialevaluation process, the fluted portion 14 and cutting tip 12 of thedrill bit 16 are properly illuminated via the illumination array 124 ofthe optical assembly 118.

[0146] Subsequent to the completion of the initial evaluation of thedrill bit 16, the same is retracted out of the optical assembly 118 bythe workhead assembly 96 and transported to a grinding assembly 130thereby. As indicated above, the angle A between the reference line RLand third reference axis RA3 is determined by the control logic of theoptical assembly 118 through the use of the images generated by thefront camera 126, with the angle A being transmitted to and storedwithin the control device. Upon the retraction of the drill bit 16 outof the optical assembly 118, the control device is operative tofacilitate the rotation of the drill bit 16 relative to the collet axisCX such that the angle A is set to about 72 degrees. Importantly, theangle A is set to 72 degrees so as to facilitate the engagement of thecutting tip 12 to the grinding assembly 130 at the proper angularorientation, as will be described in more detail below.

[0147] The process of transporting the drill bit 16 to the grindingassembly 130 is accomplished by the activation of the actuator 100 tocause the extension or advancement of the piston rod from the body whichresults in the movement of the base member 98 of the workhead assembly96 along the base member axis BX away from the optical assembly 118. Theswivel member 102 of the workhead assembly 96 is then rotated by theactivation of the first stepper motor 104 so as to place the cutting tip12 of the drill bit 16 at the proper angular orientation relative to thegrinding face of the first grinder head 138 of the grinder assembly 130based on the initial evaluation thereof. The collet shaft 108 of thecollet member 106 of the workhead assembly 96 is then indexed toward thegrinding assembly 130 by the activation of the second stepper motor 112.The movement of the collet member 108 is controlled so as to place thecutting tip 12 of the drill bit 16 into contact with the rotatinggrinding face of the first grinder head 138 (FIG. 11i). Importantly, aspreviously indicated, as the cutting tip 12 of the drill bit 16 is beingadvanced toward the grinder head 138, the locking sleeve 111 is receivedinto the aperture or support bushing 116 of the support member 114 ofthe workhead assembly 96. Such receipt prevents excessive vibration andor movement of the collet head 110 and hence the cutting tip 12 of thedrill bit 16 as the same is being ground.

[0148] After the cutting tip 12 has been placed into contact with thegrinding face of the first grinder head 138, the second stepper motor112 is activated so as to facilitate a slight retraction of the colletshaft 108 into the collet member housing 107 for purposes of creating anarrow gap between the cutting tip 12 and the grinding face. Thereafter,the second stepper motor 112 is activated so as to cause the colletshaft 108 to rotate the drill bit approximately 180°. Subsequent to suchrotation, the second stepper motor 112 is activated so as to once againfacilitate the advancement of the collet shaft 108 from the colletmember housing 107 and return the cutting tip 12 of the drill bit 16into contact with the grinding face. As will be recognized, thisprocedure must be followed to achieve the sharpening of both flutes ofthe cutting tip 12.

[0149] After both flutes of the cutting tip 12 have been re-sharpened bythe grinding face of the first grinder head 138, the same process asdescribed above is repeated in relation to the grinding face of thesecond grinder head 140. In this respect, the cutting tip 12 of thedrill bit 16 is advanced by a workhead assembly 96 into contact with therotating grinding face of the second grinder head 140, retractedtherefrom and rotated approximately 180°, and subsequently advanced backinto contact with the grinding face of the second grinder head 140.During the complete grinding process, the grinding of the cutting tip 12via the grinding face of the first grinder head 138 accomplishes a“rough” grind, with the grinding of the cutting tip 12 via the grindingface of the second grinder head 140 accomplishing a “fine” grind.

[0150] As will be recognized, the advancement of the cutting tip 12 ofthe drill bit 16 into contact with the rotating grinding face of eitherthe first or second grinder heads 138, 140 by a workhead assembly 96results in a certain amount of pressure being exerted by the cutting tip12 against a respective grinding face. The advancement of the cuttingtip 12 into contact with the grinding face too quickly or with too muchforce, or the exertion of excessive pressure by the cutting tip 12against the grinding face during the grinding operation after initialcontact has been established could result in the fracture of breakage ofthe drill bit 16 or the burning of the cutting tip 12 thereof. Toeliminate such susceptibility to breakage or burning, each grindingassembly 130 of the apparatus 10 may be outfitted with theabove-described adjustment mechanisms 300.

[0151] Importantly, each of the adjustment mechanisms 300 is operativeto retract a respective grinding face away from the cutting tip 12 ofthe drill bit 16 in the event the pressure exerted by the cutting tip 12thereagainst exceeds a prescribed level. For example, in the adjustmentmechanism 300 shown in FIG. 13, the exertion of compressive pressure bythe cutting tip 12 against the grinding face of the first grinder head138 above a prescribed level would trigger the activation of the steppermotor 306 to facilitate the rotation of the ball screw 304 in a mannerresulting in the movement of the first grinder head 138 along thegrinder head axis GH toward the stepper motor 306, and hence away fromthe cutting tip 12 of the drill bit 16. As will recognized, suchrearward movement of the first grinder head 138 alleviates the excessivepressure condition which could otherwise result in the fracture ofburning of the cutting tip 12. The determination of whether the pressureexerted by the cutting tip 12 against the grinding face of the firstgrinder head 138 exceeds the prescribed level is established by asuitable transducer element disposed within the first grinder motor 134and cooperatively engaged to the first motor shaft 135. This transducerelement is in electrical communication with the stepper motor 306 and,as indicated above, causes the first grinder head 138 to be retractedaway from the cutting tip 12 in response to an excessive pressurecondition. In the event the retraction of the first grinder head 138away from the cutting tip 12 results in the pressure level falling belowan acceptable or tolerable range, the stepper motor 306 will bere-activated to facilitate to the movement of the first grinder head 138in an opposite direction toward the cutting tip 12 so as to re-establishcontact therebetween at a pressure level within the acceptable range.

[0152] It will be recognized that the same functionality is achieved inrelation to the second grinder head 140 by mounting the second grindermotor 136 to the remaining adjustment mechanism 300. Like the firstgrinder motor 134, the second grinder motor 136 may include a pressuretransducer element which is cooperatively engaged to the associatedmotor shaft facilitating the rotatable connection of the second grinderhead 140 to the second grinder motor 136. It is contemplated that in theapparatus 10 of the present invention, the initialevaluations/measurements of the drill bit 16 and cutting tip 12 thereoffacilitated by the optical assembly 118 and control device may be usedto cause the control device to manipulate the workhead assembly 96 inmanner allowing the re-grinding operation to be completed in a mannerwherein the overall length of the drill bit 16 is reduced by only about0.002 inches. This level of accuracy is a significant improvement overprior art re-sharpening devices of lesser accuracy wherein there-grinding process typically results in a reduction in overall lengthof about 0.008 inches, thus significantly reducing the life span of thedrill bit.

[0153] After the cutting tip 12 has been re-sharpened by the grindingassembly 130, the drill bit 16 is then maneuvered by the workheadassembly 96 such that the collet axis CX is coaxially aligned with theopening 122 within the optical housing 120 of an optical assembly 118.The conveyor bar 184 of a secondary cleaning assembly 180 is thenactuated from its retracted to its extended position, thus resulting inthe placement of a quantity of cleaning putty 194 on the conveyor belt190 into horizontal alignment with the cutting tip 12 of the drill bit16. Thereafter, the actuator 100 of the workhead assembly 96 is actuatedso as to cause the retraction of the piston rod into the body, thusresulting in the movement of the base member 98 of the workhead assembly96 along the base member axis BX toward the optical assembly 118. Suchmovement is continued until such time as the cutting tip 12 is insertedinto the quantity of cleaning putty 194 upon the conveyor belt 190 ofthe secondary cleaning assembly 180 (FIG. 11j). Subsequent to suchinsertion, the conveyor bar 184 is actuated back to its retractedposition, thus resulting in the removal of the cutting tip 12 fromwithin the quantity of cleaning putty 194.

[0154] As previously explained in the section captioned SecondaryCleaning Assemblies, the return of the conveyor bar 184 to its retractedposition results in the indexing of the conveyor belt 190 a prescribedincremental distance which insures that the cutting tips 12 ofsubsequently cleaned drill bits 16 will not be inserted into the sameportion of cleaning putty 194 as the previously cleaned drill bits 16.After the cutting tip 12 of the drill bit 16 has been re-cleaned, thedrill bit 16 is re-inserted into the optical assembly 118 (FIG. 11k),with such insertion being accomplished in the same manner previouslydescribed in relation to FIG. 11h. After being cleaned but prior tobeing re-inserted into the optical assembly 118, the drill bit 16 isrotated by the workhead assembly 96 relative to the collet axis CX so asto set the angle A to 160 degrees or 20 degrees. As will be recognized,the control device is operative to facilitate such precise rotation ofthe drill bit 16 due to the original value of the angle A being storedtherein. Importantly, the rotation of the drill bit 16 such that theangle A equals 160 degrees or 20 degrees is used to optimize theillumination of the cutting tip 12 thereof by the illumination ray 124when the drill bit 16 is re-inserted into the optical assembly 118, forreasons which will be discussed in more detail below.

[0155] Referring now to FIGS. 10a-10 c, the re-insertion of the drillbit 16 into the optical assembly 118 causes the control device totrigger the performance of a final inspection or evaluation of thecutting tip 12 and fluted portion 14 thereof. More particularly,immediately upon the drill bit 16 being re-inserted into the opticalassembly 118, the top camera 128 begins generating images which allowthe control logic of the optical assembly 118 to interact with thecontrol device in a manner causing the chisel edge 200 of the cuttingtip 12 to be brought to the point of intersection between the first andsecond reference axis RA1, RA2 of the first set of cross-hairs. Theadvancement of the chisel edge 200 to this point of intersection allowsthe optical assembly 118 to determine whether the drill bit 16 has beenbroken during the grinding or re-sharpening process. In this respect, ifthe drill bit 16 has been broken, the images generated by the top camera128 will establish that at least a portion of the fluted portion 14including the cutting tip 12 is missing from the drill bit 16.

[0156] Assuming that the drill bit 16 has not been broken as a result ofthe check thereof by the optical assembly 118, the process previouslydescribed in relation to FIG. 7a is repeated for purposes of determiningor measuring the new overall length of the drill bit 16. In thisrespect, since the grinding process typically results in the shorteningof the fluted portion 14, the comparison of the new overall length ofthe drill bit 16 to the previously stored measurement thereof allows fora determination as to how much of the fluted portion 14 has been removedby the grinding process. The new overall length of the drill bit 16calculated subsequent to the completion to the regrinding of the cuttingtip 12 thereof is also transmitted to and stored within the controldevice.

[0157] Subsequent to the determination of the new overall length of thedrill bit 16, the front camera 126 then generates images which are usedto inspect or check the geometry and condition of the cutting tip 12(FIG. 10b) As seen in FIGS. 10c and 12 a-12 j, the control logic of theoptical assembly 118 is operative to interpret and evaluate the imagesgenerated by the front camera 126 regarding the geometry and conditionof the cutting tip 12, and to electrically communicate datacorresponding to such evaluation to the control device for storagetherein. Importantly, the highly sophisticated level of functionality ofthe optical assembly 118, and in particular the control logic thereof,allows for a determination of various conditions of the cutting tip 12,including:

[0158] 1. the final margin condition of the fluted portion 14 (FIG.10c);

[0159] 2. relatively minor, non-functional conditions including anoverlap condition which can impede the drill bit 16 from centeringcorrectly (FIG. 12a), a gap condition which is typically considered tobe a non-functional condition of the drill bit 16 (FIG. 12b), a negativecondition which is typically considered to be a non-functional defectwith no impact on the cutting action or symmetry of the drill bit 16when held within the specification (FIG. 12c), a flare condition whichis typically considered to be a non-functional cosmetic defect (FIG.12d), and a hook condition which is typically considered to be anon-functional condition which could result in premature wear of thecutting tip 12 (FIG. 12i); and

[0160] 3. critical cutting edge conditions, including chips on theprimary cutting edges 202 of the cutting tip 12 which prevent the drillbit 16 from cutting cleaning and efficiently (FIG. 12e), a lay backcondition (also referred to as negative rake) which allows the centersof the cutting edges 202 to be the leading cutting edges of the cuttingtip 12 verses the corner edges thereof (FIG. 12f), an offcentercondition which is characterized by a non-centralized chisel edge 200and allows for non-concentric drilling to occur (FIG. 12g), and anoffset condition which is defined by a off-centered center line CL ofthe cutting tip 12 (i.e., primary faces 204 of different thicknesses)and allows for non-concentric drilling to occur (i.e., holesout-of-round or mis-registered) FIG. 12h).

[0161] Once again, the control device is operable to process andinterpret the images generated by the front and top cameras 126, 128,and store the data obtained from the final evaluation for verificationof tolerances, for future reference, and for updating the artificialintelligence of the control device. If through this final inspection,the drill bit 16 is determined to be outside of process tolerances, thedrill bit is rejected from further processing at this time orre-evaluated for additional re-sharpening procedures. In this respect,the failure of the drill bit 16 to satisfy prescribed parameters asdetermined during the final evaluation thereof could be used to triggerthe initiation of a re-grinding operation in relation thereto. As partof the final evaluation, a determination is made by the control deviceas to whether the position of the locating ring 22 upon the shankportion 18 must be adjusted due to the shortening of the fluted portion14 resulting from the grinding process. As indicated above, there-sharpening of the cutting tip 12 (i.e., the grinding process), willtypically necessitate the re-positioning of the locating ring 22 uponthe shank portion 18 of the drill bit 16. It is contemplated that thedrill bit 16 may be provided with some type of last use indicatoradjacent the locating ring 22 for providing a visual indication that thedrill bit 16 should not be subjected to another re-grinding operation.

[0162] Upon completion of the final evaluation, the drill bit 16 istransferred from the workhead assembly 96 back to the loader assembly 62(FIG. 11l). As will be recognized, this process is accomplished in thereverse manner to that previously described in relation to FIG. 11g.Since the gripper 70 includes a pair of shaft members 72, a drill bit 16can be removed from within a workhead assembly 96 and another drill bit16 (i.e., the drill bit 16 disposed within the remaining shaft member72) inserted into the workhead assembly 96 without having to maneuverthe gripper 70 back to one of the cassette trays 54. If, during thefinal evaluation of the drill bit 16 it is determined that the geometryof the cutting tip 12 is flawed or faulted, upon the drill bit 16 beingtransferred back to the loader assembly 62, the same is immediatelytransported by the loader assembly 62 to a reject bin or similarlocation. Assuming that the cutting tip 12 is not flawed and thelocating ring 22 must be re-positioned, the loader assembly 62 thentransports the drill bit 16 to the bumper assembly 146, and inserts theshank portion 18 of the drill bit 16 into the drill seat 148 of thebumping assembly 146 (FIG. 11m). The re-positioning of the locating ring22 of the drill bit 16 by the bumping assembly 146 is accomplished inthe manner previously described in the section captioned BumpingAssembly.

[0163] After the locating ring 22 has been re-positioned via the bumpingassembly 146, the drill bit 16 is transported back to a cassette tray 54by the loader assembly 62. Importantly, the loader assembly 62 ismaneuvered by the control device so as to return the drill bit 16 to theprecise drill bit receiving hole 40 within the drill bit container 26from which it was initially removed by the loader assembly 62 (FIG.11n), thus re-packaging the drill bit 16 within the container 26.

[0164] Statistical Process Control

[0165] As indicated above, for each drill bit 16 re-sharpened by theapparatus 10 of the present invention, data corresponding to thegeometry and condition of the drill bit 16, and in particular thecutting tip 12 thereof, is transmitted to the control device and storedtherewithin. This data is generated by the control logic of the opticalcontrol assembly 118 based on the images generated by the front and topcameras 126, 128 thereof. The transmission of this data to the controldevice by virtue of its electrical communication with the opticalassembly 118 allows the control device to manipulate the various linearand/or rotational movements of the workhead assembly 96 as needed tofacilitate the required indexing of the drill bit 16, and in particularthe cutting tip 12 thereof, within the interior of the optical assembly118 for proper illumination, inspection and evaluation.

[0166] Typically, the apparatus 10 of the present invention will be usedto re-sharpen large lots of the drill bits 16. Importantly, the controldevice is provided with memory or storage capacity sufficient to allowfor the storage of the above-described information for each individualdrill bit 16 of the lot to be re-sharpened through the use of theapparatus 10. As indicated above, the data for each drill bit 16 storedwithin the control device includes its pre-grinding overall length,pre-grinding diameter, pre-grinding margin condition, post-grindingoverall length, post-grinding margin condition, and post-grindinggeometry/condition of the cutting tip 12. Advantageously, the controldevice has the capability of accumulating this data for the entire lotof drill bits 16 being re-sharpened by the apparatus 10, and to providea print-out of such data to provide to the customer. The data presentedto the customer in print-out form is lot specific. This data not onlyprovides a verification of the accuracy of the regrinding process, butalso apprises the customer with a used drill analysis (UDA). In thisrespect, the data provided in the print-out may be used to advise thecustomer that the drill bits 16 are being re-sharpened too early, andthat the same may be subjected to further use before re-sharpening isnecessary. This data can also be used to determine whether the stockremoval from the cutting tips 12 of the drill bits 16 should be reduced,whether the stock removal from the cutting tips 12 of the drill bits 16should be increased, and whether the speed of the first and secondgrinder motors 134, 136 should be increased or decreased. This data canfurther be used to facilitate the sorting of the drill bits 16 in adesired manner. For example, drill bits 16 within a certain overalllength range may be sorted or segregated to a prescribed location, withdrill bits 16 having cutting tips 12 of a similar condition being sortedinto a prescribed location.

[0167] Additional modifications and improvements of the presentinvention may also be apparent to those of ordinary skill in the art.Thus, the particular combination of parts and steps described andillustrated herein is intended to represent only one embodiment of thepresent invention, and is not intended to serve as limitations ofalternative devices within the spirit and scope of the invention.

What is claimed is:
 1. An automated method of re-sharpening a drill bithaving a shank portion and a fluted portion which defines a pair ofmargins and a cutting tip using an automated re-sharpening apparatuswhich includes at least one grinding assembly, at least one opticalassembly, at least one workhead assembly, and a loader assembly, themethod comprising the steps of: a) positioning at least one drill bit ata pick-up location; b) removing the drill bit from the pick-up locationvia the loader assembly; c) transferring the drill bit from the loaderassembly to the workhead assembly; d) conducting an initial evaluationof the drill bit via the optical assembly; e) grinding the cutting tipvia the grinding assembly according to the initial evaluation; f)conducting a final evaluation of the drill bit via the optical assembly;and g) transporting the drill bit from the workhead assembly to adrop-off location via the loader assembly.
 2. The method of claim 1wherein step (g) comprises transporting the drill bit to a prescribeddrop-off location according to the final evaluation thereof.
 3. Themethod of claim 1 wherein: step (a) comprises positioning multiple drillbits at the pick-up location; step (b) comprises removing the drill bitsfrom the pick-up location one at a time via the loader assembly; andstep (g) comprises transporting the drill bits from the workheadassembly to the drop-off location one at a time via the loader assembly.4. The method of claim 3 wherein step (g) comprises sorting the drillbits by transporting the drill bits to respective ones of multipledrop-off locations according to each of the final evaluations thereof.5. The method of claim 3 wherein the automated re-sharpening apparatusfurther includes a programmable control device electrically connected tothe grinding, optical, workhead, and loader assemblies for controllingand coordinating the operations thereof, and: step (d) comprises storingdata corresponding to the initial evaluation of each of the drill bitsin the control device; and step (f) comprises storing data correspondingto the final evaluation of each of the drill bits in the control device.6. The method of claim 5 further comprising the step of: (h) generatinga statistical process control report based on the data stored in thecontrol device.
 7. The method of claim 5 further comprising the stepsof: h) generating a used drill profile based on the data stored in thecontrol device; and i) adjusting the manner in which the cutting tips ofsubsequently processed drill bits are ground in step (e) according tothe used drill profile.
 8. The method of claim 1 wherein step (d)comprises: 1) inserting the fluted portion into the optical assembly viathe workhead assembly; 2) determining the overall length of the drillbit; 3) determining the diameter of the cutting tip; 4) determining thecondition of the margins; 5) indexing the cutting tip to a prescribedposition; and 6) removing the fluted portion from within the opticalassembly via the workhead assembly.
 9. The method of claim 8 wherein theoptical assembly is operative to generate first, second, third, andfourth reference axes, and step (2) comprises: i) indexing the cuttingtip to a first reference point on the second reference axis via theworkhead assembly; and ii) determining the distance between the firstreference point and a point of intersection between the first and secondreference axes.
 10. The method of claim 9 wherein the optical assemblyis further operative to generate a reference line and a target line, andstep (5) comprises: i) generating the reference line along the cuttingtip of the drill bit; ii) rotating the drill bit via the workheadassembly to adjust the angular orientation of the reference linerelative to the third reference axis to within a prescribed range; iii)indexing the cutting tip to a second reference point on the secondreference axis; iv) generating the target line along one of the marginsof the fluted portion; and v) rotating the drill bit via the workheadassembly as needed to cause the target line to cross the point ofintersection between the first and second reference axes.
 11. The methodof claim 1 wherein step (h) comprises: 1) inserting the fluted portioninto the optical assembly via the workhead assembly; 2) determining theoverall length of the drill bit; 3) determining the geometry of thecutting tip; 4) determining the condition of the margins; and 5)removing the fluted portion from within the optical assembly via theworkhead assembly.
 12. The method of claim 11 wherein the opticalassembly is operative to generate first, second, third, and fourthreference axes, and step (1) comprises: i) indexing the cutting tip to afirst reference point on the second reference axis via the workheadassembly; and ii) determining the distance between the first referencepoint and a point of intersection between the first and second referenceaxes.
 13. The method of claim 1 wherein the automated re-sharpeningapparatus includes a pair of optical assemblies and a pair of grindingassemblies, and steps (a)-(g) are conducted simultaneously on at leasttwo drill bits.
 14. The method of claim 1 wherein step (e) comprises: 1)moving the cutting tip into contact with the grinding assembly via theworkhead assembly; 2) moving the cutting tip away from the grindingassembly via the workhead assembly; 3) rotating the cutting tipapproximately 180° via the workhead assembly; 4) moving the cutting tipinto contact with the grinding assembly via the workhead assembly; and5) moving the cutting tip away from the grinding assembly via theworkhead assembly.
 15. The method of claim 14 wherein steps (1) and (4)each comprise retracting the grinding assembly away from the cutting tipin the event the contact pressure between the cutting tip and thegrinding assembly exceeds a prescribed level.
 16. An automated method ofre-sharpening a drill bit having a shank portion and a fluted portionwhich define the pair of margins and a cutting tip using an automatedre-sharpening apparatus which includes a pair of grinding assemblies, apair of optical assemblies, a pair of workhead assemblies, and a loaderassembly, the method comprising the steps of: a) positioning multipledrill bits at a pick-up location; b) removing the drill bits from thepick-up location one at a time via the loader assembly; c) transferringthe drill bits from the loader assembly to respective ones of theworkhead assemblies; d) conducting initial evaluations of the drill bitsvia respective ones of the optical assemblies; e) grinding the cuttingtips via respective ones of the grinding assemblies according to theinitial evaluations; f) conducting final evaluations of the drill bitsvia respective ones of the optical assemblies; and g) transporting thedrill bits from the workhead assemblies to a drop-off location via theloader assembly.
 17. An automated method of re-sharpening a drill bithaving a shank portion and a fluted portion which defines a pair ofmargins and a cutting tip using an automated re-sharpening apparatuswhich includes at least one grinding assembly and at least one opticalassembly, the method comprising the steps of: a) conducting an initialevaluation of the drill bit via the optical assembly; b) grinding thecutting tip via the grinding assembly according to the initialevaluation; c) conducting a final evaluation of the drill bit via theoptical assembly; and d) generating and storing data corresponding tothe initial and final evaluations of the drill bit.
 18. The method ofclaim 17 wherein: step (a) comprises positioning multiple drill bits ata pick-up location and transporting the drill bits to the opticalassembly one at a time; step (b) comprises transporting each of thedrill bits from the optical assembly to the grinding assembly; step (c)comprises transporting each of the drill bits from the grinding assemblyto the optical assembly; and step (d) comprises sorting the drill bitsby transporting the drill bits to respective ones of multiple drop-offlocations according to the data generated and stored in relationthereto.
 19. An automated apparatus for re-sharpening a drill bit havinga shank portion and a fluted portion which defines a pair of margins anda cutting tip, the apparatus comprising: a) a housing; b) at least oneoptical assembly attached to the housing and operative to conductinitial and final evaluations of the drill bit; c) at least one grindingassembly attached to the housing and operative to grind the cutting tipaccording to the initial evaluation conducted by the optical assembly;d) at least one workhead assembly movably attached to the housing forselectively transporting the drill bit between the optical and grindingassemblies; and e) a loader assembly movably attached to the housing forselectively transporting the drill bit from a pick-up location to theworkhead assembly and from the workhead assembly to a drop-off location.20. The apparatus of claim 19 further comprising a programmable controldevice electrically connected to the grinding, optical, workhead, andloader assemblies for controlling and coordinating the operationsthereof.
 21. The apparatus of claim 20 wherein the optical assemblycomprises: a) top and front cameras for generating images which are usedto determine the overall length of the drill bit, the diameter andgeometry of the cutting tip, and the condition of the margins, and toindex the cutting tip to selected reference points; b) an illuminationarray for illuminating the fluted portion and the cutting tip; and C)control logic which is operative to process and interpret the imagesgenerated by the top and front cameras and to interact with the controldevice in a manner regulating the movement of the workhead assembly in aprescribed manner based on the generated images.
 22. The apparatus ofclaim 20 wherein the grinding assembly comprises: a) at least onegrinder motor; b) a grinder head rotatably connected to the grindermotor and defining a grinding face; and c) an adjustment mechanismattached to the grinder motor and operative to selectively move thegrinder head into and out of contact with the cutting tip of the drillbit based upon the level of contact pressure exerted by the cutting tipagainst the grinding face.
 23. The apparatus of claim 2 wherein theadjustment mechanism comprises: a) a housing; b) an elongate ball screwrotatably mounted to the housing; c) a stepper motor mechanicallycoupled to the ball screw and operative to selectively rotate the ballscrew in either a first direction or a second direction opposite thefirst direction; and d) a linear bearing cooperatively engaged to theball screw such that the rotation of the ball screw in the firstdirection facilitates the movement of the linear bearing toward theworkhead assembly and the rotation of the ball screw in the seconddirection facilitates the movement of the linear bearing away from theworkhead assembly; and the grinder motor being attached to the linearbearing.
 24. The apparatus of claim 20 including: a pair of grindingassemblies attached to the housing; a pair of optical assembliesattached to the housing; a pair of workhead assemblies attached to thehousing; and the control device controlling and coordinating theoperations of the grinding, optical, workhead, and loader assemblies ina manner allowing the re-sharpening process to be conductedsimultaneously on at least two drill bits.